With Postfix version 2.1 and later: the SMTP server response delay after a client has made more than $smtpd_soft_error_limit errors, and fewer than $smtpd_hard_error_limit errors, without delivering mail.With Postfix version 2.0 and earlier: the SMTP server delay before sending a reject (4xx or 5xx) response, when the client has made fewer than $smtpd_soft_error_limit errors without delivering mail.
smtpd_etrn_restrictions (default: empty)
Optional SMTP server access restrictions in the context of a client ETRN request. See SMTPD_ACCESS_README, section "Delayed evaluation of SMTP access restriction lists" for a discussion of evaluation context and time.The Postfix ETRN implementation accepts only destinations that are eligible for the Postfix "fast flush" service. See the ETRN_README file for details.
Specify a list of restrictions, separated by commas and/or whitespace. Continue long lines by starting the next line with whitespace. Restrictions are applied in the order as specified; the first restriction that matches wins.
The following restrictions are specific to the domain name information received with the ETRN command.
- check_etrn_access type:table
- Search the specified access database for the ETRN domain name or its parent domains. See the access(5) manual page for details.
Other restrictions that are valid in this context:
- *
- Generic restrictions that can be used in any SMTP command context, described under smtpd_client_restrictions.
- *
- SMTP command specific restrictions described under smtpd_client_restrictions and smtpd_helo_restrictions.
Example:
smtpd_etrn_restrictions = permit_mynetworks, reject
smtpd_expansion_filter (default: see postconf -d output)
What characters are allowed in $name expansions of RBL reply templates. Characters not in the allowed set are replaced by "_". Use C like escapes to specify special characters such as whitespace.This parameter is not subjected to $parameter expansion.
This feature is available in Postfix 2.0 and later.
smtpd_forbidden_commands (default: CONNECT, GET, POST)
List of commands that causes the Postfix SMTP server to immediately terminate the session with a 221 code. This can be used to disconnect clients that obviously attempt to abuse the system. In addition to the commands listed in this parameter, commands that follow the "Label:" format of message headers will also cause a disconnect.This feature is available in Postfix 2.2 and later.
smtpd_hard_error_limit (default: normal: 20, stress: 1)
The maximal number of errors a remote SMTP client is allowed to make without delivering mail. The Postfix SMTP server disconnects when the limit is exceeded. Normally the default limit is 20, but it changes under overload to just 1 with Postfix 2.6 and later.smtpd_helo_required (default: no)
Require that a remote SMTP client introduces itself at the beginning of an SMTP session with the HELO or EHLO command.Example:
smtpd_helo_required = yes
smtpd_helo_restrictions (default: empty)
Optional restrictions that the Postfix SMTP server applies in the context of the SMTP HELO command. See SMTPD_ACCESS_README, section "Delayed evaluation of SMTP access restriction lists" for a discussion of evaluation context and time.The default is to permit everything.
Specify a list of restrictions, separated by commas and/or whitespace. Continue long lines by starting the next line with whitespace. Restrictions are applied in the order as specified; the first restriction that matches wins.
The following restrictions are specific to the hostname information received with the HELO or EHLO command.
- check_helo_access type:table
- Search the specified access(5) database for the HELO or EHLO hostname or parent domains, and execute the corresponding action.
- check_helo_mx_access type:table
- Search the specified access(5) database for the MX hosts for the HELO or EHLO hostname, and execute the corresponding action. Note: a result of "OK" is not allowed for safety reasons. Instead, use DUNNO in order to exclude specific hosts from blacklists. This feature is available in Postfix 2.1 and later.
- check_helo_ns_access type:table
- Search the specified access(5) database for the DNS servers for the HELO or EHLO hostname, and execute the corresponding action. Note: a result of "OK" is not allowed for safety reasons. Instead, use DUNNO in order to exclude specific hosts from blacklists. This feature is available in Postfix 2.1 and later.
- reject_invalid_helo_hostname (with Postfix < 2.3: reject_invalid_hostname)
-
Reject the request when the HELO or EHLO hostname syntax is
invalid.
The invalid_hostname_reject_code specifies the response code for rejected requests (default: 501). - reject_non_fqdn_helo_hostname (with Postfix < 2.3: reject_non_fqdn_hostname)
-
Reject the request when the HELO or EHLO hostname is not in
fully-qualified domain form, as required by the RFC.
The non_fqdn_reject_code parameter specifies the response code for rejected requests (default: 504). - reject_rhsbl_helo rbl_domain=d.d.d.d
- Reject the request when the HELO or EHLO hostname hostname is listed with the A record "d.d.d.d" under rbl_domain (Postfix version 2.1 and later only). If no "=d.d.d.d" is specified, reject the request when the HELO or EHLO hostname is listed with any A record under rbl_domain. See the reject_rbl_client description for additional RBL related configuration parameters. This feature is available in Postfix 2.0 and later.
- reject_unknown_helo_hostname (with Postfix < 2.3: reject_unknown_hostname)
-
Reject the request when the HELO or EHLO hostname has no DNS A
or MX record.
The unknown_hostname_reject_code parameter specifies the numerical response code for rejected requests (default: 450).
The unknown_helo_hostname_tempfail_action parameter specifies the action after a temporary DNS error (default: defer_if_permit).
Other restrictions that are valid in this context:
- *
- Generic restrictions that can be used in any SMTP command context, described under smtpd_client_restrictions.
- *
- Client hostname or network address specific restrictions described under smtpd_client_restrictions.
- *
- SMTP command specific restrictions described under smtpd_sender_restrictions or smtpd_recipient_restrictions. When sender or recipient restrictions are listed under smtpd_helo_restrictions, they have effect only with "smtpd_delay_reject = yes", so that $smtpd_helo_restrictions is evaluated at the time of the RCPT TO command.
Examples:
smtpd_helo_restrictions = permit_mynetworks, reject_invalid_helo_hostname smtpd_helo_restrictions = permit_mynetworks, reject_unknown_helo_hostname
smtpd_history_flush_threshold (default: 100)
The maximal number of lines in the Postfix SMTP server command history before it is flushed upon receipt of EHLO, RSET, or end of DATA.smtpd_junk_command_limit (default: normal: 100, stress: 1)
The number of junk commands (NOOP, VRFY, ETRN or RSET) that a remote SMTP client can send before the Postfix SMTP server starts to increment the error counter with each junk command. The junk command count is reset after mail is delivered. See also the smtpd_error_sleep_time and smtpd_soft_error_limit configuration parameters. Normally the default limit is 100, but it changes under overload to just 1 with Postfix 2.6 and later.smtpd_milters (default: empty)
A list of Milter (mail filter) applications for new mail that arrives via the Postfix smtpd(8) server. See the MILTER_README document for details.This feature is available in Postfix 2.3 and later.
smtpd_noop_commands (default: empty)
List of commands that the Postfix SMTP server replies to with "250 Ok", without doing any syntax checks and without changing state. This list overrides any commands built into the Postfix SMTP server.smtpd_null_access_lookup_key (default: <>)
The lookup key to be used in SMTP access(5) tables instead of the null sender address.smtpd_peername_lookup (default: yes)
Attempt to look up the remote SMTP client hostname, and verify that the name matches the client IP address. A client name is set to "unknown" when it cannot be looked up or verified, or when name lookup is disabled. Turning off name lookup reduces delays due to DNS lookup and increases the maximal inbound delivery rate.This feature is available in Postfix 2.3 and later.
smtpd_policy_service_max_idle (default: 300s)
The time after which an idle SMTPD policy service connection is closed.This feature is available in Postfix 2.1 and later.
smtpd_policy_service_max_ttl (default: 1000s)
The time after which an active SMTPD policy service connection is closed.This feature is available in Postfix 2.1 and later.
smtpd_policy_service_timeout (default: 100s)
The time limit for connecting to, writing to or receiving from a delegated SMTPD policy server.This feature is available in Postfix 2.1 and later.
smtpd_proxy_ehlo (default: $myhostname)
How the Postfix SMTP server announces itself to the proxy filter. By default, the Postfix hostname is used.This feature is available in Postfix 2.1 and later.
smtpd_proxy_filter (default: empty)
The hostname and TCP port of the mail filtering proxy server. The proxy receives all mail from the Postfix SMTP server, and is supposed to give the result to another Postfix SMTP server process.Specify "host:port" or "inet:host:port" for a TCP endpoint, or "unix:pathname" for a UNIX-domain endpoint. The host can be specified as an IP address or as a symbolic name; no MX lookups are done. When no "host" or "host:" are specified, the local machine is assumed. Pathname interpretation is relative to the Postfix queue directory.
This feature is available in Postfix 2.1 and later.
The "inet:" and "unix:" prefixes are available in Postfix 2.3 and later.
smtpd_proxy_timeout (default: 100s)
The time limit for connecting to a proxy filter and for sending or receiving information. When a connection fails the client gets a generic error message while more detailed information is logged to the maillog file.Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). The default time unit is s (seconds).
This feature is available in Postfix 2.1 and later.
smtpd_recipient_limit (default: 1000)
The maximal number of recipients that the Postfix SMTP server accepts per message delivery request.smtpd_recipient_overshoot_limit (default: 1000)
The number of recipients that a remote SMTP client can send in excess of the limit specified with $smtpd_recipient_limit, before the Postfix SMTP server increments the per-session error count for each excess recipient.smtpd_recipient_restrictions (default: permit_mynetworks, reject_unauth_destination)
The access restrictions that the Postfix SMTP server applies in the context of the RCPT TO command. See SMTPD_ACCESS_README, section "Delayed evaluation of SMTP access restriction lists" for a discussion of evaluation context and time.By default, the Postfix SMTP server accepts:
- *
- Mail from clients whose IP address matches $mynetworks, or:
- *
- Mail to remote destinations that match $relay_domains, except for addresses that contain sender-specified routing (user@elsewhere@domain), or:
- *
- Mail to local destinations that match $inet_interfaces or $proxy_interfaces, $mydestination, $virtual_alias_domains, or $virtual_mailbox_domains.
IMPORTANT: If you change this parameter setting, you must specify at least one of the following restrictions. Otherwise Postfix will refuse to receive mail:
reject, defer, defer_if_permit, reject_unauth_destination
Specify a list of restrictions, separated by commas and/or whitespace. Continue long lines by starting the next line with whitespace. Restrictions are applied in the order as specified; the first restriction that matches wins.
The following restrictions are specific to the recipient address that is received with the RCPT TO command.
- check_recipient_access type:table
- Search the specified access(5) database for the resolved RCPT TO address, domain, parent domains, or localpart@, and execute the corresponding action.
- check_recipient_mx_access type:table
- Search the specified access(5) database for the MX hosts for the RCPT TO domain, and execute the corresponding action. Note: a result of "OK" is not allowed for safety reasons. Instead, use DUNNO in order to exclude specific hosts from blacklists. This feature is available in Postfix 2.1 and later.
- check_recipient_ns_access type:table
- Search the specified access(5) database for the DNS servers for the RCPT TO domain, and execute the corresponding action. Note: a result of "OK" is not allowed for safety reasons. Instead, use DUNNO in order to exclude specific hosts from blacklists. This feature is available in Postfix 2.1 and later.
- permit_auth_destination
- Permit the request when one of the following is true:
- *
- Postfix is mail forwarder: the resolved RCPT TO domain matches $relay_domains or a subdomain thereof, and the address contains no sender-specified routing (user@elsewhere@domain),
- *
- Postfix is the final destination: the resolved RCPT TO domain matches $mydestination, $inet_interfaces, $proxy_interfaces, $virtual_alias_domains, or $virtual_mailbox_domains, and the address contains no sender-specified routing (user@elsewhere@domain).
- permit_mx_backup
- Permit the request when the local mail system is backup MX for the RCPT TO domain, or when the domain is an authorized destination (see permit_auth_destination for definition).
- *
- Safety: permit_mx_backup does not accept addresses that have sender-specified routing information (example: user@elsewhere@domain).
- *
- Safety: permit_mx_backup can be vulnerable to mis-use when access is not restricted with permit_mx_backup_networks.
- *
- Safety: as of Postfix version 2.3, permit_mx_backup no longer accepts the address when the local mail system is primary MX for the recipient domain. Exception: permit_mx_backup accepts the address when it specifies an authorized destination (see permit_auth_destination for definition).
- *
- Limitation: mail may be rejected in case of a temporary DNS lookup problem with Postfix prior to version 2.0.
- reject_non_fqdn_recipient
-
Reject the request when the RCPT TO address is not in
fully-qualified domain form, as required by the RFC.
The non_fqdn_reject_code parameter specifies the response code for rejected requests (default: 504). - reject_rhsbl_recipient rbl_domain=d.d.d.d
-
Reject the request when the RCPT TO domain is listed with the
A record "d.d.d.d" under rbl_domain (Postfix version
2.1 and later only). If no "=d.d.d.d" is specified, reject
the request when the RCPT TO domain is listed with
any A record under rbl_domain.
The maps_rbl_reject_code parameter specifies the response code for rejected requests (default: 554); the default_rbl_reply parameter specifies the default server reply; and the rbl_reply_maps parameter specifies tables with server replies indexed by rbl_domain. This feature is available in Postfix version 2.0 and later. - reject_unauth_destination
- Reject the request unless one of the following is true:
- *
- Postfix is mail forwarder: the resolved RCPT TO domain matches $relay_domains or a subdomain thereof, and contains no sender-specified routing (user@elsewhere@domain),
- *
-
Postfix is the final destination: the resolved RCPT TO domain
matches $mydestination, $inet_interfaces, $proxy_interfaces,
$virtual_alias_domains, or $virtual_mailbox_domains, and contains
no sender-specified routing (user@elsewhere@domain).
The relay_domains_reject_code parameter specifies the response code for rejected requests (default: 554). - reject_unknown_recipient_domain
-
Reject the request when Postfix is not final destination for
the recipient domain, and the RCPT TO domain has no DNS A or MX
record, or when it has a malformed MX record such as a record with
a zero-length MX hostname (Postfix version 2.3 and later).
The unknown_address_reject_code parameter specifies the numerical response code for rejected requests (default: 450). The response is always 450 in case of a temporary DNS error.
The unknown_address_tempfail_action parameter specifies the action after a temporary DNS error (default: defer_if_permit). - reject_unlisted_recipient (with Postfix version 2.0: check_recipient_maps)
- Reject the request when the RCPT TO address is not listed in the list of valid recipients for its domain class. See the smtpd_reject_unlisted_recipient parameter description for details. This feature is available in Postfix 2.1 and later.
- reject_unverified_recipient
-
Reject the request when mail to the RCPT TO address is known
to bounce, or when the recipient address destination is not reachable.
Address verification information is managed by the verify(8) server;
see the ADDRESS_VERIFICATION_README file for details.
The unverified_recipient_reject_code parameter specifies the numerical response code when an address is known to bounce (default: 450, change into 550 when you are confident that it is safe to do so).
The unverified_recipient_defer_code parameter specifies the numerical response code when an address probe failed due to a temporary problem (default: 450).
The unverified_recipient_tempfail_action parameter specifies the action after addres probe failure due to a temporary problem (default: defer_if_permit).
This feature is available in Postfix 2.1 and later.
Other restrictions that are valid in this context:
- *
- Generic restrictions that can be used in any SMTP command context, described under smtpd_client_restrictions.
- *
- SMTP command specific restrictions described under smtpd_client_restrictions, smtpd_helo_restrictions and smtpd_sender_restrictions.
Example:
smtpd_recipient_restrictions = permit_mynetworks, reject_unauth_destination
smtpd_reject_unlisted_recipient (default: yes)
Request that the Postfix SMTP server rejects mail for unknown recipient addresses, even when no explicit reject_unlisted_recipient access restriction is specified. This prevents the Postfix queue from filling up with undeliverable MAILER-DAEMON messages.- *
- The recipient domain matches $mydestination, $inet_interfaces or $proxy_interfaces, but the recipient is not listed in $local_recipient_maps, and $local_recipient_maps is not null.
- *
- The recipient domain matches $virtual_alias_domains but the recipient is not listed in $virtual_alias_maps.
- *
- The recipient domain matches $virtual_mailbox_domains but the recipient is not listed in $virtual_mailbox_maps, and $virtual_mailbox_maps is not null.
- *
- The recipient domain matches $relay_domains but the recipient is not listed in $relay_recipient_maps, and $relay_recipient_maps is not null.
This feature is available in Postfix 2.1 and later.
smtpd_reject_unlisted_sender (default: no)
Request that the Postfix SMTP server rejects mail from unknown sender addresses, even when no explicit reject_unlisted_sender access restriction is specified. This can slow down an explosion of forged mail from worms or viruses.- *
- The sender domain matches $mydestination, $inet_interfaces or $proxy_interfaces, but the sender is not listed in $local_recipient_maps, and $local_recipient_maps is not null.
- *
- The sender domain matches $virtual_alias_domains but the sender is not listed in $virtual_alias_maps.
- *
- The sender domain matches $virtual_mailbox_domains but the sender is not listed in $virtual_mailbox_maps, and $virtual_mailbox_maps is not null.
- *
- The sender domain matches $relay_domains but the sender is not listed in $relay_recipient_maps, and $relay_recipient_maps is not null.
This feature is available in Postfix 2.1 and later.
smtpd_restriction_classes (default: empty)
User-defined aliases for groups of access restrictions. The aliases can be specified in smtpd_recipient_restrictions etc., and on the right-hand side of a Postfix access(5) table.One major application is for implementing per-recipient UCE control. See the RESTRICTION_CLASS_README document for other examples.
smtpd_sasl_application_name (default: smtpd)
The application name that the Postfix SMTP server uses for SASL server initialization. This controls the name of the SASL configuration file. The default value is smtpd, corresponding to a SASL configuration file named smtpd.conf.This feature is available in Postfix 2.1 and 2.2. With Postfix 2.3 it was renamed to smtpd_sasl_path.
smtpd_sasl_auth_enable (default: no)
Enable SASL authentication in the Postfix SMTP server. By default, the Postfix SMTP server does not use authentication.If a remote SMTP client is authenticated, the permit_sasl_authenticated access restriction can be used to permit relay access, like this:
smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, ...
To reject all SMTP connections from unauthenticated clients, specify "smtpd_delay_reject = yes" (which is the default) and use:
smtpd_client_restrictions = permit_sasl_authenticated, reject
See the SASL_README file for SASL configuration and operation details.
smtpd_sasl_authenticated_header (default: no)
Report the SASL authenticated user name in the smtpd(8) Received message header.This feature is available in Postfix 2.3 and later.
smtpd_sasl_exceptions_networks (default: empty)
What remote SMTP clients the Postfix SMTP server will not offer AUTH support to.Some clients (Netscape 4 at least) have a bug that causes them to require a login and password whenever AUTH is offered, whether it's necessary or not. To work around this, specify, for example, $mynetworks to prevent Postfix from offering AUTH to local clients.
Specify a list of network/netmask patterns, separated by commas and/or whitespace. The mask specifies the number of bits in the network part of a host address. You can also "/file/name" or "type:table" patterns. A "/file/name" pattern is replaced by its contents; a "type:table" lookup table is matched when a table entry matches a lookup string (the lookup result is ignored). Continue long lines by starting the next line with whitespace. Specify "!pattern" to exclude an address or network block from the list. The form "!/file/name" is supported only in Postfix version 2.4 and later.
Note: IP version 6 address information must be specified inside [] in the smtpd_sasl_exceptions_networks value, and in files specified with "/file/name". IP version 6 addresses contain the ":" character, and would otherwise be confused with a "type:table" pattern.
Example:
smtpd_sasl_exceptions_networks = $mynetworks
This feature is available in Postfix 2.1 and later.
smtpd_sasl_local_domain (default: empty)
The name of the Postfix SMTP server's local SASL authentication realm.By default, the local authentication realm name is the null string.
Examples:
smtpd_sasl_local_domain = $mydomain smtpd_sasl_local_domain = $myhostname
smtpd_sasl_path (default: smtpd)
Implementation-specific information that the Postfix SMTP server passes through to the SASL plug-in implementation that is selected with smtpd_sasl_type. Typically this specifies the name of a configuration file or rendezvous point.This feature is available in Postfix 2.3 and later. In earlier releases it was called smtpd_sasl_application_name.
smtpd_sasl_security_options (default: noanonymous)
Postfix SMTP server SASL security options; as of Postfix 2.3 the list of available features depends on the SASL server implementation that is selected with smtpd_sasl_type.The following security features are defined for the cyrus server SASL implementation:
Restrict what authentication mechanisms the Postfix SMTP server will offer to the client. The list of available authentication mechanisms is system dependent.
Specify zero or more of the following:
- noplaintext
- Disallow methods that use plaintext passwords.
- noactive
- Disallow methods subject to active (non-dictionary) attack.
- nodictionary
- Disallow methods subject to passive (dictionary) attack.
- noanonymous
- Disallow methods that allow anonymous authentication.
- forward_secrecy
- Only allow methods that support forward secrecy (Dovecot only).
- mutual_auth
- Only allow methods that provide mutual authentication (not available with Cyrus SASL version 1).
By default, the Postfix SMTP server accepts plaintext passwords but not anonymous logins.
Warning: it appears that clients try authentication methods in the order as advertised by the server (e.g., PLAIN ANONYMOUS CRAM-MD5) which means that if you disable plaintext passwords, clients will log in anonymously, even when they should be able to use CRAM-MD5. So, if you disable plaintext logins, disable anonymous logins too. Postfix treats anonymous login as no authentication.
Example:
smtpd_sasl_security_options = noanonymous, noplaintext
smtpd_sasl_tls_security_options (default: $smtpd_sasl_security_options)
The SASL authentication security options that the Postfix SMTP server uses for TLS encrypted SMTP sessions.This feature is available in Postfix 2.2 and later.
smtpd_sasl_type (default: cyrus)
The SASL plug-in type that the Postfix SMTP server should use for authentication. The available types are listed with the "postconf -a" command.This feature is available in Postfix 2.3 and later.
smtpd_sender_login_maps (default: empty)
Optional lookup table with the SASL login names that own sender (MAIL FROM) addresses.Specify zero or more "type:table" lookup tables. With lookups from indexed files such as DB or DBM, or from networked tables such as NIS, LDAP or SQL, the following search operations are done with a sender address of user@domain:
- 1) user@domain
- This table lookup is always done and has the highest precedence.
- 2) user
- This table lookup is done only when the domain part of the sender address matches $myorigin, $mydestination, $inet_interfaces or $proxy_interfaces.
- 3) @domain
- This table lookup is done last and has the lowest precedence.
In all cases the result of table lookup must be either "not found" or a list of SASL login names separated by comma and/or whitespace.
smtpd_sender_restrictions (default: empty)
Optional restrictions that the Postfix SMTP server applies in the context of the MAIL FROM command. See SMTPD_ACCESS_README, section "Delayed evaluation of SMTP access restriction lists" for a discussion of evaluation context and time.The default is to permit everything.
Specify a list of restrictions, separated by commas and/or whitespace. Continue long lines by starting the next line with whitespace. Restrictions are applied in the order as specified; the first restriction that matches wins.
The following restrictions are specific to the sender address received with the MAIL FROM command.
- check_sender_access type:table
- Search the specified access(5) database for the MAIL FROM address, domain, parent domains, or localpart@, and execute the corresponding action.
- check_sender_mx_access type:table
- Search the specified access(5) database for the MX hosts for the MAIL FROM address, and execute the corresponding action. Note: a result of "OK" is not allowed for safety reasons. Instead, use DUNNO in order to exclude specific hosts from blacklists. This feature is available in Postfix 2.1 and later.
- check_sender_ns_access type:table
- Search the specified access(5) database for the DNS servers for the MAIL FROM address, and execute the corresponding action. Note: a result of "OK" is not allowed for safety reasons. Instead, use DUNNO in order to exclude specific hosts from blacklists. This feature is available in Postfix 2.1 and later.
- reject_authenticated_sender_login_mismatch
- Enforces the reject_sender_login_mismatch restriction for authenticated clients only. This feature is available in Postfix version 2.1 and later.
- reject_non_fqdn_sender
-
Reject the request when the MAIL FROM address is not in
fully-qualified domain form, as required by the RFC.
The non_fqdn_reject_code parameter specifies the response code for rejected requests (default: 504). - reject_rhsbl_sender rbl_domain=d.d.d.d
-
Reject the request when the MAIL FROM domain is listed with
the A record "d.d.d.d" under rbl_domain (Postfix
version 2.1 and later only). If no "=d.d.d.d" is specified,
reject the request when the MAIL FROM domain is
listed with any A record under rbl_domain.
The maps_rbl_reject_code parameter specifies the response code for rejected requests (default: 554); the default_rbl_reply parameter specifies the default server reply; and the rbl_reply_maps parameter specifies tables with server replies indexed by rbl_domain. This feature is available in Postfix 2.0 and later. - reject_sender_login_mismatch
- Reject the request when $smtpd_sender_login_maps specifies an owner for the MAIL FROM address, but the client is not (SASL) logged in as that MAIL FROM address owner; or when the client is (SASL) logged in, but the client login name doesn't own the MAIL FROM address according to $smtpd_sender_login_maps.
- reject_unauthenticated_sender_login_mismatch
- Enforces the reject_sender_login_mismatch restriction for unauthenticated clients only. This feature is available in Postfix version 2.1 and later.
- reject_unknown_sender_domain
-
Reject the request when Postfix is not final destination for
the sender address, and the MAIL FROM address has no DNS A or MX
record, or when it has a malformed MX record such as a record with
a zero-length MX hostname (Postfix version 2.3 and later).
The unknown_address_reject_code parameter specifies the numerical response code for rejected requests (default: 450). The response is always 450 in case of a temporary DNS error.
The unknown_address_tempfail_action parameter specifies the action after a temporary DNS error (default: defer_if_permit). - reject_unlisted_sender
- Reject the request when the MAIL FROM address is not listed in the list of valid recipients for its domain class. See the smtpd_reject_unlisted_sender parameter description for details. This feature is available in Postfix 2.1 and later.
- reject_unverified_sender
-
Reject the request when mail to the MAIL FROM address is known to
bounce, or when the sender address destination is not reachable.
Address verification information is managed by the verify(8) server;
see the ADDRESS_VERIFICATION_README file for details.
The unverified_sender_reject_code parameter specifies the numerical response code when an address is known to bounce (default: 450, change into 550 when you are confident that it is safe to do so).
The unverified_sender_defer_code specifies the numerical response code when an address address probe failed due to a temporary problem (default: 450).
The unverified_sender_tempfail_action parameter specifies the action after address probe failure due to a temporary problem (default: defer_if_permit).
This feature is available in Postfix 2.1 and later.
Other restrictions that are valid in this context:
- *
- Generic restrictions that can be used in any SMTP command context, described under smtpd_client_restrictions.
- *
- SMTP command specific restrictions described under smtpd_client_restrictions and smtpd_helo_restrictions.
- *
- SMTP command specific restrictions described under smtpd_recipient_restrictions. When recipient restrictions are listed under smtpd_sender_restrictions, they have effect only with "smtpd_delay_reject = yes", so that $smtpd_sender_restrictions is evaluated at the time of the RCPT TO command.
Examples:
smtpd_sender_restrictions = reject_unknown_sender_domain smtpd_sender_restrictions = reject_unknown_sender_domain, check_sender_access hash:/etc/postfix/access
smtpd_soft_error_limit (default: 10)
The number of errors a remote SMTP client is allowed to make without delivering mail before the Postfix SMTP server slows down all its responses.- *
- With Postfix version 2.1 and later, the Postfix SMTP server delays all responses by $smtpd_error_sleep_time seconds.
- *
- With Postfix versions 2.0 and earlier, the Postfix SMTP server delays all responses by (number of errors) seconds.
smtpd_starttls_timeout (default: 300s)
The time limit for Postfix SMTP server write and read operations during TLS startup and shutdown handshake procedures.This feature is available in Postfix 2.2 and later.
smtpd_timeout (default: normal: 300s, stress: 10s)
The time limit for sending a Postfix SMTP server response and for receiving a remote SMTP client request. Normally the default limit is 300s, but it changes under overload to just 10s with Postfix 2.6 and later.Note: if you set SMTP time limits to very large values you may have to update the global ipc_timeout parameter.
Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). The default time unit is s (seconds).
smtpd_tls_CAfile (default: empty)
A file containing (PEM format) CA certificates of root CAs trusted to sign either remote SMTP client certificates or intermediate CA certificates. These are loaded into memory before the smtpd(8) server enters the chroot jail. If the number of trusted roots is large, consider using smtpd_tls_CApath instead, but note that the latter directory must be present in the chroot jail if the smtpd(8) server is chrooted. This file may also be used to augment the server certificate trust chain, but it is best to include all the required certificates directly in the server certificate file.By default (see smtpd_tls_ask_ccert), client certificates are not requested, and smtpd_tls_CAfile should remain empty. If you do make use of client certificates, the distinguished names (DNs) of the certificate authorities listed in smtpd_tls_CAfile are sent to the remote SMTP client in the client certificate request message. MUAs with multiple client certificates may use the list of preferred certificate authorities to select the correct client certificate. You may want to put your "preferred" CA or CAs in this file, and install other trusted CAs in $smtpd_tls_CApath.
Example:
smtpd_tls_CAfile = /etc/postfix/CAcert.pem
This feature is available in Postfix 2.2 and later.
smtpd_tls_CApath (default: empty)
A directory containing (PEM format) CA certificates of root CAs trusted to sign either remote SMTP client certificates or intermediate CA certificates. Do not forget to create the necessary "hash" links with, for example, "$OPENSSL_HOME/bin/c_rehash /etc/postfix/certs". To use smtpd_tls_CApath in chroot mode, this directory (or a copy) must be inside the chroot jail.By default (see smtpd_tls_ask_ccert), client certificates are not requested, and smtpd_tls_CApath should remain empty. In contrast to smtp_tls_CAfile, DNs of certificate authorities installed in $smtpd_tls_CApath are not included in the client certificate request message. MUAs with multiple client certificates may use the list of preferred certificate authorities to select the correct client certificate. You may want to put your "preferred" CA or CAs in $smtp_tls_CAfile, and install the remaining trusted CAs in $smtpd_tls_CApath.
Example:
smtpd_tls_CApath = /etc/postfix/certs
This feature is available in Postfix 2.2 and later.
smtpd_tls_always_issue_session_ids (default: yes)
Force the Postfix SMTP server to issue a TLS session id, even when TLS session caching is turned off (smtpd_tls_session_cache_database is empty). This behavior is compatible with Postfix < 2.3.With Postfix 2.3 and later the Postfix SMTP server can disable session id generation when TLS session caching is turned off. This keeps clients from caching sessions that almost certainly cannot be re-used.
By default, the Postfix SMTP server always generates TLS session ids. This works around a known defect in mail client applications such as MS Outlook, and may also prevent interoperability issues with other MTAs.
Example:
smtpd_tls_always_issue_session_ids = no
This feature is available in Postfix 2.3 and later.
smtpd_tls_ask_ccert (default: no)
Ask a remote SMTP client for a client certificate. This information is needed for certificate based mail relaying with, for example, the permit_tls_clientcerts feature.Some clients such as Netscape will either complain if no certificate is available (for the list of CAs in $smtpd_tls_CAfile) or will offer multiple client certificates to choose from. This may be annoying, so this option is "off" by default.
This feature is available in Postfix 2.2 and later.
smtpd_tls_auth_only (default: no)
When TLS encryption is optional in the Postfix SMTP server, do not announce or accept SASL authentication over unencrypted connections.This feature is available in Postfix 2.2 and later.
smtpd_tls_ccert_verifydepth (default: 9)
The verification depth for remote SMTP client certificates. A depth of 1 is sufficient if the issuing CA is listed in a local CA file.The default verification depth is 9 (the OpenSSL default) for compatibility with earlier Postfix behavior. Prior to Postfix 2.5, the default value was 5, but the limit was not actually enforced. If you have set this to a lower non-default value, certificates with longer trust chains may now fail to verify. Certificate chains with 1 or 2 CAs are common, deeper chains are more rare and any number between 5 and 9 should suffice in practice. You can choose a lower number if, for example, you trust certificates directly signed by an issuing CA but not any CAs it delegates to.
This feature is available in Postfix 2.2 and later.
smtpd_tls_cert_file (default: empty)
File with the Postfix SMTP server RSA certificate in PEM format. This file may also contain the Postfix SMTP server private RSA key.Public Internet MX hosts without certificates signed by a "reputable" CA must generate, and be prepared to present to most clients, a self-signed or private-CA signed certificate. The client will not be able to authenticate the server, but unless it is running Postfix 2.3 or similar software, it will still insist on a server certificate.
For servers that are not public Internet MX hosts, Postfix 2.3 supports configurations with no certificates. This entails the use of just the anonymous TLS ciphers, which are not supported by typical SMTP clients. Since such clients will not, as a rule, fall back to plain text after a TLS handshake failure, the server will be unable to receive email from TLS enabled clients. To avoid accidental configurations with no certificates, Postfix 2.3 enables certificate-less operation only when the administrator explicitly sets "smtpd_tls_cert_file = none". This ensures that new Postfix configurations will not accidentally run with no certificates.
Both RSA and DSA certificates are supported. When both types are present, the cipher used determines which certificate will be presented to the client. For Netscape and OpenSSL clients without special cipher choices the RSA certificate is preferred.
To enable a remote SMTP client to verify the Postfix SMTP server certificate, the issuing CA certificates must be made available to the client. You should include the required certificates in the server certificate file, the server certificate first, then the issuing CA(s) (bottom-up order).
Example: the certificate for "server.example.com" was issued by "intermediate CA" which itself has a certificate of "root CA". Create the server.pem file with "cat server_cert.pem intermediate_CA.pem root_CA.pem > server.pem".
If you also want to verify client certificates issued by these CAs, you can add the CA certificates to the smtpd_tls_CAfile, in which case it is not necessary to have them in the smtpd_tls_cert_file or smtpd_tls_dcert_file.
A certificate supplied here must be usable as an SSL server certificate and hence pass the "openssl verify -purpose sslserver ..." test.
Example:
smtpd_tls_cert_file = /etc/postfix/server.pem
This feature is available in Postfix 2.2 and later.
smtpd_tls_cipherlist (default: empty)
Obsolete Postfix < 2.3 control for the Postfix SMTP server TLS cipher list. It is easy to create inter-operability problems by choosing a non-default cipher list. Do not use a non-default TLS cipherlist for MX hosts on the public Internet. Clients that begin the TLS handshake, but are unable to agree on a common cipher, may not be able to send any email to the SMTP server. Using a restricted cipher list may be more appropriate for a dedicated MSA or an internal mailhub, where one can exert some control over the TLS software and settings of the connecting clients.Note: do not use "" quotes around the parameter value.
This feature is available with Postfix version 2.2. It is not used with Postfix 2.3 and later; use smtpd_tls_mandatory_ciphers instead.
smtpd_tls_ciphers (default: export)
The minimum TLS cipher grade that the Postfix SMTP server will use with opportunistic TLS encryption. Cipher types listed in smtpd_tls_exclude_ciphers are excluded from the base definition of the selected cipher grade. The default value "export" ensures maximum inter-operability. Because encryption is optional, stronger controls are not appropriate, and this setting SHOULD NOT be changed unless the change is essential.When TLS is mandatory the cipher grade is chosen via the smtpd_tls_mandatory_ciphers configuration parameter, see there for syntax details.
Example:
smtpd_tls_ciphers = export
This feature is available in Postfix 2.6 and later. With earlier Postfix releases only the smtpd_tls_mandatory_ciphers parameter is implemented, and opportunistic TLS always uses "export" or better (i.e. all) ciphers.
smtpd_tls_dcert_file (default: empty)
File with the Postfix SMTP server DSA certificate in PEM format. This file may also contain the Postfix SMTP server private DSA key.See the discussion under smtpd_tls_cert_file for more details.
Example:
smtpd_tls_dcert_file = /etc/postfix/server-dsa.pem
This feature is available in Postfix 2.2 and later.
smtpd_tls_dh1024_param_file (default: empty)
File with DH parameters that the Postfix SMTP server should use with EDH ciphers.Instead of using the exact same parameter sets as distributed with other TLS packages, it is more secure to generate your own set of parameters with something like the following command:
openssl gendh -out /etc/postfix/dh_1024.pem -2 1024
Your actual source for entropy may differ. Some systems have /dev/random; on other system you may consider using the "Entropy Gathering Daemon EGD", available at http://egd.sourceforge.net/
Example:
smtpd_tls_dh1024_param_file = /etc/postfix/dh_1024.pem
This feature is available with Postfix version 2.2.
smtpd_tls_dh512_param_file (default: empty)
File with DH parameters that the Postfix SMTP server should use with EDH ciphers.See also the discussion under the smtpd_tls_dh1024_param_file configuration parameter.
Example:
smtpd_tls_dh512_param_file = /etc/postfix/dh_512.pem
This feature is available with Postfix version 2.2.
smtpd_tls_dkey_file (default: $smtpd_tls_dcert_file)
File with the Postfix SMTP server DSA private key in PEM format. This file may be combined with the Postfix SMTP server DSA certificate file specified with $smtpd_tls_dcert_file.The private key must be accessible without a pass-phrase, i.e. it must not be encrypted. File permissions should grant read-only access to the system superuser account ("root"), and no access to anyone else.
This feature is available in Postfix 2.2 and later.
smtpd_tls_eccert_file (default: empty)
File with the Postfix SMTP server ECDSA certificate in PEM format. This file may also contain the Postfix SMTP server private ECDSA key.See the discussion under smtpd_tls_cert_file for more details.
Example:
smtpd_tls_eccert_file = /etc/postfix/ecdsa-scert.pem
This feature is available in Postfix 2.6 and later, when Postfix is compiled and linked with OpenSSL 0.9.9 or later.
smtpd_tls_eckey_file (default: $smtpd_tls_eccert_file)
File with the Postfix SMTP server ECDSA private key in PEM format. This file may be combined with the Postfix SMTP server ECDSA certificate file specified with $smtpd_tls_eccert_file.The private key must be accessible without a pass-phrase, i.e. it must not be encrypted. File permissions should grant read-only access to the system superuser account ("root"), and no access to anyone else.
This feature is available in Postfix 2.6 and later, when Postfix is compiled and linked with OpenSSL 0.9.9 or later.
smtpd_tls_eecdh_grade (default: see postconf -d output)
The Postfix SMTP server security grade for ephemeral elliptic-curve Diffie-Hellman (EECDH) key exchange.The available choices are:
- none
- Don't use EECDH. Ciphers based on EECDH key exchange will be disabled. This is the default in official Postfix releases (mail_version = major.minor.patchlevel).
- strong
- Use EECDH with approximately 128 bits of security at a reasonable computational cost. This is the current best-practice trade-off between security and computational efficiency. This is the default in Postfix snapshot releases (mail_version = major.minor-releasedate).
- ultra
- Use EECDH with approximately 192 bits of security at computational cost that is approximately twice as high as 128 bit strength ECC. Barring significant progress in attacks on elliptic curve crypto-systems, the "strong" curve is sufficient for most users.
This feature is available in Postfix 2.6 and later, when it is compiled and linked with OpenSSL 0.9.9 or later.
smtpd_tls_exclude_ciphers (default: empty)
List of ciphers or cipher types to exclude from the SMTP server cipher list at all TLS security levels. Excluding valid ciphers can create interoperability problems. DO NOT exclude ciphers unless it is essential to do so. This is not an OpenSSL cipherlist; it is a simple list separated by whitespace and/or commas. The elements are a single cipher, or one or more "+" separated cipher properties, in which case only ciphers matching all the properties are excluded.Examples (some of these will cause problems):
smtpd_tls_exclude_ciphers = aNULL smtpd_tls_exclude_ciphers = MD5, DES smtpd_tls_exclude_ciphers = DES+MD5 smtpd_tls_exclude_ciphers = AES256-SHA, DES-CBC3-MD5 smtpd_tls_exclude_ciphers = kEDH+aRSA
The first setting disables anonymous ciphers. The next setting disables ciphers that use the MD5 digest algorithm or the (single) DES encryption algorithm. The next setting disables ciphers that use MD5 and DES together. The next setting disables the two ciphers "AES256-SHA" and "DES-CBC3-MD5". The last setting disables ciphers that use "EDH" key exchange with RSA authentication.
This feature is available in Postfix 2.3 and later.
smtpd_tls_fingerprint_digest (default: md5)
The message digest algorithm used to construct client-certificate fingerprints for check_ccert_access and permit_tls_clientcerts. The default algorithm is md5, for backwards compatibility with Postfix releases prior to 2.5.The best practice algorithm is now sha1. Recent advances in hash function cryptanalysis have led to md5 being deprecated in favor of sha1. However, as long as there are no known "second pre-image" attacks against md5, its use in this context can still be considered safe.
While additional digest algorithms are often available with OpenSSL's libcrypto, only those used by libssl in SSL cipher suites are available to Postfix. For now this means just md5 or sha1.
To find the fingerprint of a specific certificate file, with a specific digest algorithm, run:
$ openssl x509 -noout -fingerprint -digest -in certfile.pem
The text to the right of "=" sign is the desired fingerprint. For example:
$ openssl x509 -noout -fingerprint -sha1 -in cert.pem SHA1 Fingerprint=D4:6A:AB:19:24:79:F8:32:BB:A6:CB:66:82:C0:8E:9B:EE:29:A8:1A
Example: client-certificate access table, with sha1 fingerprints:
/etc/postfix/main.cf: smtpd_tls_fingerprint_digest = sha1 smtpd_client_restrictions = check_ccert_access hash:/etc/postfix/access, reject
/etc/postfix/access: # Action folded to next line... AF:88:7C:AD:51:95:6F:36:96:F6:01:FB:2E:48:CD:AB:49:25:A2:3B OK 85:16:78:FD:73:6E:CE:70:E0:31:5F:0D:3C:C8:6D:C4:2C:24:59:E1 permit_auth_destination
This feature is available in Postfix 2.5 and later.
smtpd_tls_key_file (default: $smtpd_tls_cert_file)
File with the Postfix SMTP server RSA private key in PEM format. This file may be combined with the Postfix SMTP server RSA certificate file specified with $smtpd_tls_cert_file.The private key must be accessible without a pass-phrase, i.e. it must not be encrypted. File permissions should grant read-only access to the system superuser account ("root"), and no access to anyone else.
smtpd_tls_loglevel (default: 0)
Enable additional Postfix SMTP server logging of TLS activity. Each logging level also includes the information that is logged at a lower logging level.- 0 Disable logging of TLS activity.
- 1 Log TLS handshake and certificate information.
- 2 Log levels during TLS negotiation.
- 3 Log hexadecimal and ASCII dump of TLS negotiation process.
- 4 Also log hexadecimal and ASCII dump of complete transmission after STARTTLS.
Use "smtpd_tls_loglevel = 3" only in case of problems. Use of loglevel 4 is strongly discouraged.
This feature is available in Postfix 2.2 and later.
smtpd_tls_mandatory_ciphers (default: medium)
The minimum TLS cipher grade that the Postfix SMTP server will use with mandatory TLS encryption. Cipher types listed in smtpd_tls_mandatory_exclude_ciphers or smtpd_tls_exclude_ciphers are excluded from the base definition of the selected cipher grade. See smtpd_tls_ciphers for cipher controls that apply to opportunistic TLS.The following cipher grades are supported:
- export
- Enable the mainstream "EXPORT" grade or better OpenSSL ciphers. This is the most appropriate setting for public MX hosts, and is always used with opportunistic TLS encryption. The underlying cipherlist is specified via the tls_export_cipherlist configuration parameter, which you are strongly encouraged to not change. The default value of tls_export_cipherlist includes anonymous ciphers, but these are automatically filtered out if the server is configured to ask for client certificates. If you must always exclude anonymous ciphers, set "smtpd_tls_exclude_ciphers = aNULL". To exclude anonymous ciphers only when TLS is enforced, set "smtpd_tls_mandatory_exclude_ciphers = aNULL".
- low
- Enable the mainstream "LOW" grade or better OpenSSL ciphers. The underlying cipherlist is specified via the tls_low_cipherlist configuration parameter, which you are strongly encouraged to not change. The default value of tls_low_cipherlist includes anonymous ciphers, but these are automatically filtered out if the server is configured to ask for client certificates. If you must always exclude anonymous ciphers, set "smtpd_tls_exclude_ciphers = aNULL". To exclude anonymous ciphers only when TLS is enforced, set "smtpd_tls_mandatory_exclude_ciphers = aNULL".
- medium
- Enable the mainstream "MEDIUM" grade or better OpenSSL ciphers. These are essentially the 128-bit or stronger ciphers. This is the default minimum strength for mandatory TLS encryption. MSAs that enforce TLS and have clients that do not support any "MEDIUM" or "HIGH" grade ciphers, may need to configure a weaker ("low" or "export") minimum cipher grade. The underlying cipherlist is specified via the tls_medium_cipherlist configuration parameter, which you are strongly encouraged to not change. The default value of tls_medium_cipherlist includes anonymous ciphers, but these are automatically filtered out if the server is configured to ask for client certificates. If you must always exclude anonymous ciphers, set "smtpd_tls_exclude_ciphers = aNULL". To exclude anonymous ciphers only when TLS is enforced, set "smtpd_tls_mandatory_exclude_ciphers = aNULL".
- high
- Enable only the mainstream "HIGH" grade OpenSSL ciphers. The underlying cipherlist is specified via the tls_high_cipherlist configuration parameter, which you are strongly encouraged to not change. The default value of tls_high_cipherlist includes anonymous ciphers, but these are automatically filtered out if the server is configured to ask for client certificates. If you must always exclude anonymous ciphers, set "smtpd_tls_exclude_ciphers = aNULL". To exclude anonymous ciphers only when TLS is enforced, set "smtpd_tls_mandatory_exclude_ciphers = aNULL".
- null
- Enable only the "NULL" OpenSSL ciphers, these provide authentication without encryption. This setting is only appropriate in the rare case that all clients are prepared to use NULL ciphers (not normally enabled in TLS clients). The underlying cipherlist is specified via the tls_null_cipherlist configuration parameter, which you are strongly encouraged to not change. The default value of tls_null_cipherlist excludes anonymous ciphers (OpenSSL 0.9.8 has NULL ciphers that offer data integrity without encryption or authentication).
This feature is available in Postfix 2.3 and later.
smtpd_tls_mandatory_exclude_ciphers (default: empty)
Additional list of ciphers or cipher types to exclude from the SMTP server cipher list at mandatory TLS security levels. This list works in addition to the exclusions listed with smtpd_tls_exclude_ciphers (see there for syntax details).This feature is available in Postfix 2.3 and later.
smtpd_tls_mandatory_protocols (default: SSLv3, TLSv1)
The SSL/TLS protocols accepted by the Postfix SMTP server with mandatory TLS encryption. If the list is empty, the server supports all available SSL/TLS protocol versions. A non-empty value is a list of protocol names separated by whitespace, commas or colons. The supported protocol names are "SSLv2", "SSLv3" and "TLSv1", and are not case sensitive.With Postfix >= 2.5 the parameter syntax is expanded to support protocol exclusions. One can now explicitly exclude SSLv2 by setting "smtpd_tls_mandatory_protocols = !SSLv2". To exclude both SSLv2 and SSLv3 set "smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3". Listing the protocols to include, rather than protocols to exclude, is still supported, use the form you find more intuitive.
Since SSL version 2 has known protocol weaknesses and is now deprecated, the default setting excludes "SSLv2". This means that by default, SSL version 2 will not be used at the "encrypt" security level.
Example:
smtpd_tls_mandatory_protocols = TLSv1 # Alternative form with Postfix >= 2.5: smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3
This feature is available in Postfix 2.3 and later.
smtpd_tls_protocols (default: empty)
List of TLS protocols that the Postfix SMTP server will exclude or include with opportunistic TLS encryption. This parameter SHOULD be left at its default empty value, allowing all protocols to be used with opportunistic TLS.In main.cf the values are separated by whitespace, commas or colons. An empty value means allow all protocols. The valid protocol names, (see \fBfBSSL_get_version(3)), are "SSLv2", "SSLv3" and "TLSv1". In smtp_tls_policy_maps table entries, "protocols" attribute values are separated by a colon.
To include a protocol list its name, to exclude it, prefix the name with a "!" character. To exclude SSLv2 even for opportunistic TLS set "smtpd_tls_protocols = !SSLv2". To exclude both "SSLv2" and "SSLv3" set "smtpd_tls_protocols = !SSLv2, !SSLv3". Explicitly listing the protocols to include, is supported, but not recommended. OpenSSL provides no mechanisms for excluding protocols not known at compile-time. If Postfix is linked against an OpenSSL library that supports additional protocol versions, they cannot be excluded using either syntax.
Example:
smtpd_tls_protocols = !SSLv2
This feature is available in Postfix 2.6 and later.
smtpd_tls_received_header (default: no)
Request that the Postfix SMTP server produces Received: message headers that include information about the protocol and cipher used, as well as the client CommonName and client certificate issuer CommonName. This is disabled by default, as the information may be modified in transit through other mail servers. Only information that was recorded by the final destination can be trusted.This feature is available in Postfix 2.2 and later.
smtpd_tls_req_ccert (default: no)
With mandatory TLS encryption, require a trusted remote SMTP client certificate in order to allow TLS connections to proceed. This option implies "smtpd_tls_ask_ccert = yes".When TLS encryption is optional, this setting is ignored with a warning written to the mail log.
This feature is available in Postfix 2.2 and later.
smtpd_tls_security_level (default: empty)
The SMTP TLS security level for the Postfix SMTP server; when a non-empty value is specified, this overrides the obsolete parameters smtpd_use_tls and smtpd_enforce_tls. This parameter is ignored with "smtpd_tls_wrappermode = yes".Specify one of the following security levels:
- none
- TLS will not be used.
- may
- Opportunistic TLS: announce STARTTLS support to SMTP clients, but do not require that clients use TLS encryption.
- encrypt
- Mandatory TLS encryption: announce STARTTLS support to SMTP clients, and require that clients use TLS encryption. According to RFC 2487 this MUST NOT be applied in case of a publicly-referenced SMTP server. Instead, this option should be used only on dedicated servers.
Note 1: the "fingerprint", "verify" and "secure" levels are not supported here. The Postfix SMTP server logs a warning and uses "encrypt" instead. To verify SMTP client certificates, see TLS_README for a discussion of the smtpd_tls_ask_ccert, smtpd_tls_req_ccert, and permit_tls_clientcerts features.
Note 2: The parameter setting "smtpd_tls_security_level = encrypt" implies "smtpd_tls_auth_only = yes".
Note 3: when invoked via "sendmail -bs", Postfix will never offer STARTTLS due to insufficient privileges to access the server private key. This is intended behavior.
This feature is available in Postfix 2.3 and later.
smtpd_tls_session_cache_database (default: empty)
Name of the file containing the optional Postfix SMTP server TLS session cache. Specify a database type that supports enumeration, such as btree or sdbm; there is no need to support concurrent access. The file is created if it does not exist. The smtpd(8) daemon does not use this parameter directly, rather the cache is implemented indirectly in the tlsmgr(8) daemon. This means that per-smtpd-instance master.cf overrides of this parameter are not effective. Note, that each of the cache databases supported by tlsmgr(8) daemon: $smtpd_tls_session_cache_database, $smtp_tls_session_cache_database (and with Postfix 2.3 and later $lmtp_tls_session_cache_database), needs to be stored separately. It is not at this time possible to store multiple caches in a single database.Note: dbm databases are not suitable. TLS session objects are too large.
As of version 2.5, Postfix no longer uses root privileges when opening this file. The file should now be stored under the Postfix-owned data_directory. As a migration aid, an attempt to open the file under a non-Postfix directory is redirected to the Postfix-owned data_directory, and a warning is logged.
Example:
smtpd_tls_session_cache_database = btree:/var/lib/postfix/smtpd_scache
This feature is available in Postfix 2.2 and later.
smtpd_tls_session_cache_timeout (default: 3600s)
The expiration time of Postfix SMTP server TLS session cache information. A cache cleanup is performed periodically every $smtpd_tls_session_cache_timeout seconds. As with $smtpd_tls_session_cache_database, this parameter is implemented in the tlsmgr(8) daemon and therefore per-smtpd-instance master.cf overrides are not possible.This feature is available in Postfix 2.2 and later.
smtpd_tls_wrappermode (default: no)
Run the Postfix SMTP server in the non-standard "wrapper" mode, instead of using the STARTTLS command.If you want to support this service, enable a special port in master.cf, and specify "-o smtpd_tls_wrappermode=yes" on the SMTP server's command line. Port 465 (smtps) was once chosen for this purpose.
This feature is available in Postfix 2.2 and later.
smtpd_use_tls (default: no)
Opportunistic TLS: announce STARTTLS support to SMTP clients, but do not require that clients use TLS encryption.Note: when invoked via "sendmail -bs", Postfix will never offer STARTTLS due to insufficient privileges to access the server private key. This is intended behavior.
This feature is available in Postfix 2.2 and later. With Postfix 2.3 and later use smtpd_tls_security_level instead.
soft_bounce (default: no)
Safety net to keep mail queued that would otherwise be returned to the sender. This parameter disables locally-generated bounces, and prevents the Postfix SMTP server from rejecting mail permanently, by changing 5xx reply codes into 4xx. However, soft_bounce is no cure for address rewriting mistakes or mail routing mistakes.Example:
soft_bounce = yes
stale_lock_time (default: 500s)
The time after which a stale exclusive mailbox lockfile is removed. This is used for delivery to file or mailbox.Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). The default time unit is s (seconds).
stress (default: empty)
This feature is documented in the STRESS_README document.This feature is available in Postfix 2.5 and later.
strict_7bit_headers (default: no)
Reject mail with 8-bit text in message headers. This blocks mail from poorly written applications.This feature should not be enabled on a general purpose mail server, because it is likely to reject legitimate email.
This feature is available in Postfix 2.0 and later.
strict_8bitmime (default: no)
Enable both strict_7bit_headers and strict_8bitmime_body.This feature should not be enabled on a general purpose mail server, because it is likely to reject legitimate email.
This feature is available in Postfix 2.0 and later.
strict_8bitmime_body (default: no)
Reject 8-bit message body text without 8-bit MIME content encoding information. This blocks mail from poorly written applications.Unfortunately, this also rejects majordomo approval requests when the included request contains valid 8-bit MIME mail, and it rejects bounces from mailers that do not MIME encapsulate 8-bit content (for example, bounces from qmail or from old versions of Postfix).
This feature should not be enabled on a general purpose mail server, because it is likely to reject legitimate email.
This feature is available in Postfix 2.0 and later.
strict_mailbox_ownership (default: yes)
Defer delivery when a mailbox file is not owned by its recipient. The default setting is not backwards compatible.This feature is available in Postfix 2.5.3 and later.
strict_mime_encoding_domain (default: no)
Reject mail with invalid Content-Transfer-Encoding: information for the message/* or multipart/* MIME content types. This blocks mail from poorly written software.This feature should not be enabled on a general purpose mail server, because it will reject mail after a single violation.
This feature is available in Postfix 2.0 and later.
strict_rfc821_envelopes (default: no)
Require that addresses received in SMTP MAIL FROM and RCPT TO commands are enclosed with <>, and that those addresses do not contain RFC 822 style comments or phrases. This stops mail from poorly written software.By default, the Postfix SMTP server accepts RFC 822 syntax in MAIL FROM and RCPT TO addresses.
sun_mailtool_compatibility (default: no)
Obsolete SUN mailtool compatibility feature. Instead, use "mailbox_delivery_lock = dotlock".swap_bangpath (default: yes)
Enable the rewriting of "site!user" into "user@site". This is necessary if your machine is connected to UUCP networks. It is enabled by default.Note: with Postfix version 2.2, message header address rewriting happens only when one of the following conditions is true:
- *
- The message is received with the Postfix sendmail(1) command,
- *
- The message is received from a network client that matches $local_header_rewrite_clients,
- *
- The message is received from the network, and the remote_header_rewrite_domain parameter specifies a non-empty value.
To get the behavior before Postfix version 2.2, specify "local_header_rewrite_clients = static:all".
Example:
swap_bangpath = no
syslog_facility (default: mail)
The syslog facility of Postfix logging. Specify a facility as defined in syslog.conf(5). The default facility is "mail".Warning: a non-default syslog_facility setting takes effect only after a Postfix process has completed initialization. Errors during process initialization will be logged with the default facility. Examples are errors while parsing the command line arguments, and errors while accessing the Postfix main.cf configuration file.
syslog_name (default: see postconf -d output)
The mail system name that is prepended to the process name in syslog records, so that "smtpd" becomes, for example, "postfix/smtpd".Warning: a non-default syslog_name setting takes effect only after a Postfix process has completed initialization. Errors during process initialization will be logged with the default name. Examples are errors while parsing the command line arguments, and errors while accessing the Postfix main.cf configuration file.
tcp_windowsize (default: 0)
An optional workaround for routers that break TCP window scaling. Specify a value > 0 and < 65536 to enable this feature. With Postfix TCP servers (smtpd(8), qmqpd(8)), this feature is implemented by the Postfix master(8) daemon.To change this parameter without stopping Postfix, you need to first terminate all Postfix TCP servers:
# postconf -e master_service_disable=inet # postfix reload
This immediately terminates all processes that accept network connections. Next, you enable Postfix TCP servers with the updated tcp_windowsize setting:
# postconf -e tcp_windowsize=65535 master_service_disable= # postfix reload
If you skip these steps with a running Postfix system, then the tcp_windowsize change will work only for Postfix TCP clients (smtp(8), lmtp(8)).
This feature is available in Postfix 2.6 and later.
tls_daemon_random_bytes (default: 32)
The number of pseudo-random bytes that an smtp(8) or smtpd(8) process requests from the tlsmgr(8) server in order to seed its internal pseudo random number generator (PRNG). The default of 32 bytes (equivalent to 256 bits) is sufficient to generate a 128bit (or 168bit) session key.This feature is available in Postfix 2.2 and later.
tls_eecdh_strong_curve (default: prime256v1)
The elliptic curve used by the SMTP server for sensibly strong ephemeral ECDH key exchange. This curve is used by the Postfix SMTP server when "smtpd_tls_eecdh_grade = strong". The phrase "sensibly strong" means approximately 128-bit security based on best known attacks. The selected curve must be implemented by OpenSSL (as reported by ecparam(1) with the "-list_curves" option) and be one of the curves listed in Section 5.1.1 of RFC 4492. You should not generally change this setting.This default curve is specified in NSA "Suite B" Cryptography (see http://www.nsa.gov/ia/industry/crypto_suite_b.cfm) for information classified as SECRET.
Note: elliptic curve names are poorly standardized; different standards groups are assigning different names to the same underlying curves. The curve with the X9.62 name "prime256v1" is also known under the SECG name "secp256r1", but OpenSSL does not recognize the latter name.
This feature is available in Postfix 2.6 and later, when it is compiled and linked with OpenSSL 0.9.9 or later.
tls_eecdh_ultra_curve (default: secp384r1)
The elliptic curve used by the SMTP server for maximally strong ephemeral ECDH key exchange. This curve is used by the Postfix SMTP server when "smtpd_tls_eecdh_grade = ultra". The phrase "maximally strong" means approximately 192-bit security based on best known attacks. This additional strength comes at a significant computational cost, most users should instead set "smtpd_tls_eecdh_grade = strong". The selected curve must be implemented by OpenSSL (as reported by ecparam(1) with the "-list_curves" option) and be one of the curves listed in Section 5.1.1 of RFC 4492. You should not generally change this setting.This default "ultra" curve is specified in NSA "Suite B" Cryptography (see http://www.nsa.gov/ia/industry/crypto_suite_b.cfm) for information classified as TOP SECRET.
This feature is available in Postfix 2.6 and later, when it is compiled and linked with OpenSSL 0.9.9 or later.
tls_export_cipherlist (default: ALL:+RC4:@STRENGTH)
The OpenSSL cipherlist for "EXPORT" or higher grade ciphers. This defines the meaning of the "export" setting in smtpd_tls_mandatory_ciphers, smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. This is the cipherlist for the opportunistic ("may") TLS client security level and is the default cipherlist for the SMTP server. You are strongly encouraged to not change this setting.This feature is available in Postfix 2.3 and later.
tls_high_cipherlist (default: ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH)
The OpenSSL cipherlist for "HIGH" grade ciphers. This defines the meaning of the "high" setting in smtpd_tls_mandatory_ciphers, smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. You are strongly encouraged to not change this setting.This feature is available in Postfix 2.3 and later.
tls_low_cipherlist (default: ALL:!EXPORT:+RC4:@STRENGTH)
The OpenSSL cipherlist for "LOW" or higher grade ciphers. This defines the meaning of the "low" setting in smtpd_tls_mandatory_ciphers, smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. You are strongly encouraged to not change this setting.This feature is available in Postfix 2.3 and later.
tls_medium_cipherlist (default: ALL:!EXPORT:!LOW:+RC4:@STRENGTH)
The OpenSSL cipherlist for "MEDIUM" or higher grade ciphers. This defines the meaning of the "medium" setting in smtpd_tls_mandatory_ciphers, smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. This is the default cipherlist for mandatory TLS encryption in the TLS client (with anonymous ciphers disabled when verifying server certificates). You are strongly encouraged to not change this setting.This feature is available in Postfix 2.3 and later.
tls_null_cipherlist (default: eNULL:!aNULL)
The OpenSSL cipherlist for "NULL" grade ciphers that provide authentication without encryption. This defines the meaning of the "null" setting in smtpd_mandatory_tls_ciphers, smtp_tls_mandatory_ciphers and lmtp_tls_mandatory_ciphers. You are strongly encouraged to not change this setting.This feature is available in Postfix 2.3 and later.
tls_random_bytes (default: 32)
The number of bytes that tlsmgr(8) reads from $tls_random_source when (re)seeding the in-memory pseudo random number generator (PRNG) pool. The default of 32 bytes (256 bits) is good enough for 128bit symmetric keys. If using EGD or a device file, a maximum of 255 bytes is read.This feature is available in Postfix 2.2 and later.
tls_random_exchange_name (default: see postconf -d output)
Name of the pseudo random number generator (PRNG) state file that is maintained by tlsmgr(8). The file is created when it does not exist, and its length is fixed at 1024 bytes.As of version 2.5, Postfix no longer uses root privileges when opening this file, and the default file location was changed from ${config_directory}/prng_exch to ${data_directory}/prng_exch. As a migration aid, an attempt to open the file under a non-Postfix directory is redirected to the Postfix-owned data_directory, and a warning is logged.
This feature is available in Postfix 2.2 and later.
tls_random_prng_update_period (default: 3600s)
The time between attempts by tlsmgr(8) to save the state of the pseudo random number generator (PRNG) to the file specified with $tls_random_exchange_name.This feature is available in Postfix 2.2 and later.
tls_random_reseed_period (default: 3600s)
The maximal time between attempts by tlsmgr(8) to re-seed the in-memory pseudo random number generator (PRNG) pool from external sources. The actual time between re-seeding attempts is calculated using the PRNG, and is between 0 and the time specified.This feature is available in Postfix 2.2 and later.
tls_random_source (default: see postconf -d output)
The external entropy source for the in-memory tlsmgr(8) pseudo random number generator (PRNG) pool. Be sure to specify a non-blocking source. If this source is not a regular file, the entropy source type must be prepended: egd:/path/to/egd_socket for a source with EGD compatible socket interface, or dev:/path/to/device for a device file.Note: on OpenBSD systems specify /dev/arandom when /dev/urandom gives timeout errors.
This feature is available in Postfix 2.2 and later.
trace_service_name (default: trace)
The name of the trace service. This service is implemented by the bounce(8) daemon and maintains a record of mail deliveries and produces a mail delivery report when verbose delivery is requested with "sendmail -v".This feature is available in Postfix 2.1 and later.
transport_delivery_slot_cost (default: $default_delivery_slot_cost)
A transport-specific override for the default_delivery_slot_cost parameter value, where transport is the master.cf name of the message delivery transport.transport_delivery_slot_discount (default: $default_delivery_slot_discount)
A transport-specific override for the default_delivery_slot_discount parameter value, where transport is the master.cf name of the message delivery transport.transport_delivery_slot_loan (default: $default_delivery_slot_loan)
A transport-specific override for the default_delivery_slot_loan parameter value, where transport is the master.cf name of the message delivery transport.transport_destination_concurrency_failed_cohort_limit (default: $default_destination_concurrency_failed_cohort_limit)
A transport-specific override for the default_destination_concurrency_failed_cohort_limit parameter value, where transport is the master.cf name of the message delivery transport.This feature is available in Postfix 2.5 and later.
transport_destination_concurrency_limit (default: $default_destination_concurrency_limit)
A transport-specific override for the default_destination_concurrency_limit parameter value, where transport is the master.cf name of the message delivery transport.transport_destination_concurrency_negative_feedback (default: $default_destination_concurrency_negative_feedback)
A transport-specific override for the default_destination_concurrency_negative_feedback parameter value, where transport is the master.cf name of the message delivery transport.This feature is available in Postfix 2.5 and later.
transport_destination_concurrency_positive_feedback (default: $default_destination_concurrency_positive_feedback)
A transport-specific override for the default_destination_concurrency_positive_feedback parameter value, where transport is the master.cf name of the message delivery transport.This feature is available in Postfix 2.5 and later.
transport_destination_rate_delay (default: $default_destination_rate_delay)
A transport-specific override for the default_destination_rate_delay parameter value, where transport is the master.cf name of the message delivery transport.This feature is available in Postfix 2.5 and later.
transport_destination_recipient_limit (default: $default_destination_recipient_limit)
A transport-specific override for the default_destination_recipient_limit parameter value, where transport is the master.cf name of the message delivery transport.transport_extra_recipient_limit (default: $default_extra_recipient_limit)
A transport-specific override for the default_extra_recipient_limit parameter value, where transport is the master.cf name of the message delivery transport.transport_initial_destination_concurrency (default: $initial_destination_concurrency)
A transport-specific override for the initial_destination_concurrency parameter value, where transport is the master.cf name of the message delivery transport.This feature is available in Postfix 2.5 and later.
transport_maps (default: empty)
Optional lookup tables with mappings from recipient address to (message delivery transport, next-hop destination). See transport(5) for details.Specify zero or more "type:table" lookup tables. If you use this feature with local files, run "postmap /etc/postfix/transport" after making a change.
For safety reasons, as of Postfix 2.3 this feature does not allow $number substitutions in regular expression maps.
Examples:
transport_maps = dbm:/etc/postfix/transport transport_maps = hash:/etc/postfix/transport
transport_minimum_delivery_slots (default: $default_minimum_delivery_slots)
A transport-specific override for the default_minimum_delivery_slots parameter value, where transport is the master.cf name of the message delivery transport.transport_recipient_limit (default: $default_recipient_limit)
A transport-specific override for the default_recipient_limit parameter value, where transport is the master.cf name of the message delivery transport.transport_recipient_refill_delay (default: $default_recipient_refill_delay)
A transport-specific override for the default_recipient_refill_delay parameter value, where transport is the master.cf name of the message delivery transport.This feature is available in Postfix 2.4 and later.
transport_recipient_refill_limit (default: $default_recipient_refill_limit)
A transport-specific override for the default_recipient_refill_limit parameter value, where transport is the master.cf name of the message delivery transport.This feature is available in Postfix 2.4 and later.
transport_retry_time (default: 60s)
The time between attempts by the Postfix queue manager to contact a malfunctioning message delivery transport.Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). The default time unit is s (seconds).
transport_time_limit (default: $command_time_limit)
A transport-specific override for the command_time_limit parameter value, where transport is the master.cf name of the message delivery transport.trigger_timeout (default: 10s)
The time limit for sending a trigger to a Postfix daemon (for example, the pickup(8) or qmgr(8) daemon). This time limit prevents programs from getting stuck when the mail system is under heavy load.Time units: s (seconds), m (minutes), h (hours), d (days), w (weeks). The default time unit is s (seconds).
undisclosed_recipients_header (default: To: undisclosed-recipients:;)
Message header that the Postfix cleanup(8) server inserts when a message contains no To: or Cc: message header. With Postfix 2.4 and later, specify an empty value to disable this feature.unknown_address_reject_code (default: 450)
The numerical Postfix SMTP server response code when a sender or recipient address is rejected by the reject_unknown_sender_domain or reject_unknown_recipient_domain restriction. The response is always 450 in case of a temporary DNS error.Do not change this unless you have a complete understanding of RFC 2821.
unknown_address_tempfail_action (default: $reject_tempfail_action)
The Postfix SMTP server's action when reject_unknown_sender_domain or reject_unknown_recipient_domain fail due to a temporary error condition. Specify "defer" to defer the remote SMTP client request immediately. With the default "defer_if_permit" action, the Postfix SMTP server continues to look for opportunities to reject mail, and defers the client request only if it would otherwise be accepted.This feature is available in Postfix 2.6 and later.
unknown_client_reject_code (default: 450)
The numerical Postfix SMTP server response code when a client without valid address <=> name mapping is rejected by the reject_unknown_client_hostname restriction. The SMTP server always replies with 450 when the mapping failed due to a temporary error condition.Do not change this unless you have a complete understanding of RFC 2821.
unknown_helo_hostname_tempfail_action (default: $reject_tempfail_action)
The Postfix SMTP server's action when reject_unknown_helo_hostname fails due to an temporary error condition. Specify "defer" to defer the remote SMTP client request immediately. With the default "defer_if_permit" action, the Postfix SMTP server continues to look for opportunities to reject mail, and defers the client request only if it would otherwise be accepted.This feature is available in Postfix 2.6 and later.
unknown_hostname_reject_code (default: 450)
The numerical Postfix SMTP server response code when the hostname specified with the HELO or EHLO command is rejected by the reject_unknown_helo_hostname restriction.Do not change this unless you have a complete understanding of RFC 2821.
unknown_local_recipient_reject_code (default: 550)
The numerical Postfix SMTP server response code when a recipient address is local, and $local_recipient_maps specifies a list of lookup tables that does not match the recipient. A recipient address is local when its domain matches $mydestination, $proxy_interfaces or $inet_interfaces.The default setting is 550 (reject mail) but it is safer to initially use 450 (try again later) so you have time to find out if your local_recipient_maps settings are OK.
Example:
unknown_local_recipient_reject_code = 450
This feature is available in Postfix 2.0 and later.
unknown_relay_recipient_reject_code (default: 550)
The numerical Postfix SMTP server reply code when a recipient address matches $relay_domains, and relay_recipient_maps specifies a list of lookup tables that does not match the recipient address.This feature is available in Postfix 2.0 and later.
unknown_virtual_alias_reject_code (default: 550)
The SMTP server reply code when a recipient address matches $virtual_alias_domains, and $virtual_alias_maps specifies a list of lookup tables that does not match the recipient address.This feature is available in Postfix 2.0 and later.
unknown_virtual_mailbox_reject_code (default: 550)
The SMTP server reply code when a recipient address matches $virtual_mailbox_domains, and $virtual_mailbox_maps specifies a list of lookup tables that does not match the recipient address.This feature is available in Postfix 2.0 and later.
unverified_recipient_defer_code (default: 450)
The numerical Postfix SMTP server response when a recipient address probe fails due to a temporary error condition.Unlike elsewhere in Postfix, you can specify 250 in order to accept the address anyway.
Do not change this unless you have a complete understanding of RFC 2821.
This feature is available in Postfix 2.6 and later.
unverified_recipient_reject_code (default: 450)
The numerical Postfix SMTP server response when a recipient address is rejected by the reject_unverified_recipient restriction.Unlike elsewhere in Postfix, you can specify 250 in order to accept the address anyway.
Do not change this unless you have a complete understanding of RFC 2821.
This feature is available in Postfix 2.1 and later.
unverified_recipient_reject_reason (default: empty)
The Postfix SMTP server's reply when rejecting mail with reject_unverified_recipient. Do not include the numeric SMTP reply code or the enhanced status code. By default, the response includes actual address verification details.Example:
unverified_recipient_reject_reason = Recipient address lookup failed
This feature is available in Postfix 2.6 and later.
unverified_recipient_tempfail_action (default: $reject_tempfail_action)
The Postfix SMTP server's action when reject_unverified_recipient fails due to a temporary error condition. Specify "defer" to defer the remote SMTP client request immediately. With the default "defer_if_permit" action, the Postfix SMTP server continues to look for opportunities to reject mail, and defers the client request only if it would otherwise be accepted.This feature is available in Postfix 2.6 and later.
unverified_sender_defer_code (default: 450)
The numerical Postfix SMTP server response code when a sender address probe fails due to a temporary error condition.Unlike elsewhere in Postfix, you can specify 250 in order to accept the address anyway.
Do not change this unless you have a complete understanding of RFC 2821.
This feature is available in Postfix 2.6 and later.
unverified_sender_reject_code (default: 450)
The numerical Postfix SMTP server response code when a recipient address is rejected by the reject_unverified_sender restriction.Unlike elsewhere in Postfix, you can specify 250 in order to accept the address anyway.
Do not change this unless you have a complete understanding of RFC 2821.
This feature is available in Postfix 2.1 and later.
unverified_sender_reject_reason (default: empty)
The Postfix SMTP server's reply when rejecting mail with reject_unverified_sender. Do not include the numeric SMTP reply code or the enhanced status code. By default, the response includes actual address verification details.Example:
unverified_sender_reject_reason = Sender address lookup failed
This feature is available in Postfix 2.6 and later.
unverified_sender_tempfail_action (default: $reject_tempfail_action)
The Postfix SMTP server's action when reject_unverified_sender fails due to a temporary error condition. Specify "defer" to defer the remote SMTP client request immediately. With the default "defer_if_permit" action, the Postfix SMTP server continues to look for opportunities to reject mail, and defers the client request only if it would otherwise be accepted.This feature is available in Postfix 2.6 and later.
verp_delimiter_filter (default: -=+)
The characters Postfix accepts as VERP delimiter characters on the Postfix sendmail(1) command line and in SMTP commands.This feature is available in Postfix 1.1 and later.
virtual_alias_domains (default: $virtual_alias_maps)
Postfix is final destination for the specified list of virtual alias domains, that is, domains for which all addresses are aliased to addresses in other local or remote domains. The SMTP server validates recipient addresses with $virtual_alias_maps and rejects non-existent recipients. See also the virtual alias domain class in the ADDRESS_CLASS_README fileThis feature is available in Postfix 2.0 and later. The default value is backwards compatible with Postfix version 1.1.
The default value is $virtual_alias_maps so that you can keep all information about virtual alias domains in one place. If you have many users, it is better to separate information that changes more frequently (virtual address -> local or remote address mapping) from information that changes less frequently (the list of virtual domain names).
Specify a list of host or domain names, "/file/name" or "type:table" patterns, separated by commas and/or whitespace. A "/file/name" pattern is replaced by its contents; a "type:table" lookup table is matched when a table entry matches a lookup string (the lookup result is ignored). Continue long lines by starting the next line with whitespace. Specify "!pattern" to exclude a host or domain name from the list. The form "!/file/name" is supported only in Postfix version 2.4 and later.
See also the VIRTUAL_README and ADDRESS_CLASS_README documents for further information.
Example:
virtual_alias_domains = virtual1.tld virtual2.tld
virtual_alias_expansion_limit (default: 1000)
The maximal number of addresses that virtual alias expansion produces from each original recipient.This feature is available in Postfix 2.1 and later.
virtual_alias_maps (default: $virtual_maps)
Optional lookup tables that alias specific mail addresses or domains to other local or remote address. The table format and lookups are documented in virtual(5). For an overview of Postfix address manipulations see the ADDRESS_REWRITING_README document.This feature is available in Postfix 2.0 and later. The default value is backwards compatible with Postfix version 1.1.
If you use this feature with indexed files, run "postmap /etc/postfix/virtual" after changing the file.
Examples:
virtual_alias_maps = dbm:/etc/postfix/virtual virtual_alias_maps = hash:/etc/postfix/virtual
virtual_alias_recursion_limit (default: 1000)
The maximal nesting depth of virtual alias expansion. Currently the recursion limit is applied only to the left branch of the expansion graph, so the depth of the tree can in the worst case reach the sum of the expansion and recursion limits. This may change in the future.This feature is available in Postfix 2.1 and later.
virtual_destination_concurrency_limit (default: $default_destination_concurrency_limit)
The maximal number of parallel deliveries to the same destination via the virtual message delivery transport. This limit is enforced by the queue manager. The message delivery transport name is the first field in the entry in the master.cf file.virtual_destination_recipient_limit (default: $default_destination_recipient_limit)
The maximal number of recipients per message for the virtual message delivery transport. This limit is enforced by the queue manager. The message delivery transport name is the first field in the entry in the master.cf file.Setting this parameter to a value of 1 changes the meaning of virtual_destination_concurrency_limit from concurrency per domain into concurrency per recipient.
virtual_gid_maps (default: empty)
Lookup tables with the per-recipient group ID for virtual(8) mailbox delivery.In a lookup table, specify a left-hand side of<EMAIL_ADDRESS>to match any user in the specified domain that does not have a specific<EMAIL_ADDRESS>entry.
When a recipient address has an optional address extension (user+foo@domain.tld), the virtual(8) delivery agent looks up the full address first, and when the lookup fails, it looks up the unextended address (user@domain.tld).
Note 1: for security reasons, the virtual(8) delivery agent disallows regular expression substitution of $1 etc. in regular expression lookup tables, because that would open a security hole.
Note 2: for security reasons, the virtual(8) delivery agent will silently ignore requests to use the proxymap(8) server. Instead it will open the table directly. Before Postfix version 2.2, the virtual(8) delivery agent will terminate with a fatal error.
virtual_mailbox_base (default: empty)
A prefix that the virtual(8) delivery agent prepends to all pathname results from $virtual_mailbox_maps table lookups. This is a safety measure to ensure that an out of control map doesn't litter the file system with mailboxes. While virtual_mailbox_base could be set to "/", this setting isn't recommended.Example:
virtual_mailbox_base = /var/mail
virtual_mailbox_domains (default: $virtual_mailbox_maps)
Postfix is final destination for the specified list of domains; mail is delivered via the $virtual_transport mail delivery transport. By default this is the Postfix virtual(8) delivery agent. The SMTP server validates recipient addresses with $virtual_mailbox_maps and rejects mail for non-existent recipients. See also the virtual mailbox domain class in the ADDRESS_CLASS_README file.This parameter expects the same syntax as the mydestination configuration parameter.
This feature is available in Postfix 2.0 and later. The default value is backwards compatible with Postfix version 1.1.
virtual_mailbox_limit (default: 51200000)
The maximal size in bytes of an individual mailbox or maildir file, or zero (no limit).virtual_mailbox_lock (default: see postconf -d output)
How to lock a UNIX-style virtual(8) mailbox before attempting delivery. For a list of available file locking methods, use the "postconf -l" command.This setting is ignored with maildir style delivery, because such deliveries are safe without application-level locks.
Note 1: the dotlock method requires that the recipient UID or GID has write access to the parent directory of the recipient's mailbox file.
Note 2: the default setting of this parameter is system dependent.
virtual_mailbox_maps (default: empty)
Optional lookup tables with all valid addresses in the domains that match $virtual_mailbox_domains.In a lookup table, specify a left-hand side of<EMAIL_ADDRESS>to match any user in the specified domain that does not have a specific<EMAIL_ADDRESS>entry.
The virtual(8) delivery agent uses this table to look up the per-recipient mailbox or maildir pathname. If the lookup result ends in a slash ("/"), maildir-style delivery is carried out, otherwise the path is assumed to specify a UNIX-style mailbox file. Note that $virtual_mailbox_base is unconditionally prepended to this path.
When a recipient address has an optional address extension (user+foo@domain.tld), the virtual(8) delivery agent looks up the full address first, and when the lookup fails, it looks up the unextended address (user@domain.tld).
Note 1: for security reasons, the virtual(8) delivery agent disallows regular expression substitution of $1 etc. in regular expression lookup tables, because that would open a security hole.
Note 2: for security reasons, the virtual(8) delivery agent will silently ignore requests to use the proxymap(8) server. Instead it will open the table directly. Before Postfix version 2.2, the virtual(8) delivery agent will terminate with a fatal error.
virtual_maps (default: empty)
Optional lookup tables with a) names of domains for which all addresses are aliased to addresses in other local or remote domains, and b) addresses that are aliased to addresses in other local or remote domains. Available before Postfix version 2.0. With Postfix version 2.0 and later, this is replaced by separate controls: virtual_alias_domains and virtual_alias_maps.virtual_minimum_uid (default: 100)
The minimum user ID value that the virtual(8) delivery agent accepts as a result from $virtual_uid_maps table lookup. Returned values less than this will be rejected, and the message will be deferred.virtual_transport (default: virtual)
The default mail delivery transport and next-hop destination for final delivery to domains listed with $virtual_mailbox_domains. This information can be overruled with the transport(5) table.Specify a string of the form transport:nexthop, where transport is the name of a mail delivery transport defined in master.cf. The :nexthop part is optional. For more details see the transport(5) manual page.
This feature is available in Postfix 2.0 and later.
virtual_uid_maps (default: empty)
Lookup tables with the per-recipient user ID that the virtual(8) delivery agent uses while writing to the recipient's mailbox.In a lookup table, specify a left-hand side of<EMAIL_ADDRESS>to match any user in the specified domain that does not have a specific<EMAIL_ADDRESS>entry.
When a recipient address has an optional address extension (user+foo@domain.tld), the virtual(8) delivery agent looks up the full address first, and when the lookup fails, it looks up the unextended address (user@domain.tld).
Note 1: for security reasons, the virtual(8) delivery agent disallows regular expression substitution of $1 etc. in regular expression lookup tables, because that would open a security hole.
Note 2: for security reasons, the virtual(8) delivery agent will silently ignore requests to use the proxymap(8) server. Instead it will open the table directly. Before Postfix version 2.2, the virtual(8) delivery agent will terminate with a fatal error.
SEE ALSO
postconf(1), Postfix configuration parameter maintenance master(5), Postfix daemon configuration maintenance
LICENSE
The Secure Mailer license must be distributed with this software.AUTHOR(S)
Wietse Venema IBM T.J. Watson Research P.O. Box 704 Yorktown Heights, NY 10598, USA
Index
- NAME
- SYNOPSIS
- DESCRIPTION
- 2bounce_notice_recipient (default: postmaster)
- access_map_defer_code (default: 450)
- access_map_reject_code (default: 554)
- address_verify_default_transport (default: $default_transport)
- address_verify_local_transport (default: $local_transport)
- address_verify_map (default: empty)
- address_verify_negative_cache (default: yes)
- address_verify_negative_expire_time (default: 3d)
- address_verify_negative_refresh_time (default: 3h)
- address_verify_poll_count (default: 3)
- address_verify_poll_delay (default: 3s)
- address_verify_positive_expire_time (default: 31d)
- address_verify_positive_refresh_time (default: 7d)
- address_verify_relay_transport (default: $relay_transport)
- address_verify_relayhost (default: $relayhost)
- address_verify_sender (default: $double_bounce_sender)
- address_verify_sender_dependent_relayhost_maps (default: $sender_dependent_relayhost_maps)
- address_verify_service_name (default: verify)
- address_verify_transport_maps (default: $transport_maps)
- address_verify_virtual_transport (default: $virtual_transport)
- alias_database (default: see postconf -d output)
- alias_maps (default: see postconf -d output)
- allow_mail_to_commands (default: alias, forward)
- allow_mail_to_files (default: alias, forward)
- allow_min_user (default: no)
- allow_percent_hack (default: yes)
- allow_untrusted_routing (default: no)
- alternate_config_directories (default: empty)
- always_add_missing_headers (default: no)
- always_bcc (default: empty)
- anvil_rate_time_unit (default: 60s)
- anvil_status_update_time (default: 600s)
- append_at_myorigin (default: yes)
- append_dot_mydomain (default: yes)
- application_event_drain_time (default: 100s)
- authorized_flush_users (default: static:anyone)
- authorized_mailq_users (default: static:anyone)
- authorized_submit_users (default: static:anyone)
- authorized_verp_clients (default: $mynetworks)
- backwards_bounce_logfile_compatibility (default: yes)
- berkeley_db_create_buffer_size (default: 16777216)
- berkeley_db_read_buffer_size (default: 131072)
- best_mx_transport (default: empty)
- biff (default: yes)
- body_checks (default: empty)
- body_checks_size_limit (default: 51200)
- bounce_notice_recipient (default: postmaster)
- bounce_queue_lifetime (default: 5d)
- bounce_service_name (default: bounce)
- bounce_size_limit (default: 50000)
- bounce_template_file (default: empty)
- broken_sasl_auth_clients (default: no)
- canonical_classes (default: envelope_sender, envelope_recipient, header_sender, header_recipient)
- canonical_maps (default: empty)
- cleanup_service_name (default: cleanup)
- command_directory (default: see postconf -d output)
- command_execution_directory (default: empty)
- command_expansion_filter (default: see postconf -d output)
- command_time_limit (default: 1000s)
- config_directory (default: see postconf -d output)
- connection_cache_protocol_timeout (default: 5s)
- connection_cache_service_name (default: scache)
- connection_cache_status_update_time (default: 600s)
- connection_cache_ttl_limit (default: 2s)
- content_filter (default: empty)
- cyrus_sasl_config_path (default: empty)
- daemon_directory (default: see postconf -d output)
- daemon_timeout (default: 18000s)
- data_directory (default: see postconf -d output)
- debug_peer_level (default: 2)
- debug_peer_list (default: empty)
- debugger_command (default: empty)
- default_database_type (default: see postconf -d output)
- default_delivery_slot_cost (default: 5)
- default_delivery_slot_discount (default: 50)
- default_delivery_slot_loan (default: 3)
- default_destination_concurrency_failed_cohort_limit (default: 1)
- default_destination_concurrency_limit (default: 20)
- default_destination_concurrency_negative_feedback (default: 1)
- default_destination_concurrency_positive_feedback (default: 1)
- default_destination_rate_delay (default: 0s)
- default_destination_recipient_limit (default: 50)
- default_extra_recipient_limit (default: 1000)
- default_minimum_delivery_slots (default: 3)
- default_privs (default: nobody)
- default_process_limit (default: 100)
- default_rbl_reply (default: see postconf -d output)
- default_recipient_limit (default: 20000)
- default_recipient_refill_delay (default: 5s)
- default_recipient_refill_limit (default: 100)
- default_transport (default: smtp)
- default_verp_delimiters (default: +=)
- defer_code (default: 450)
- defer_service_name (default: defer)
- defer_transports (default: empty)
- delay_logging_resolution_limit (default: 2)
- delay_notice_recipient (default: postmaster)
- delay_warning_time (default: 0h)
- deliver_lock_attempts (default: 20)
- deliver_lock_delay (default: 1s)
- destination_concurrency_feedback_debug (default: no)
- detect_8bit_encoding_header (default: yes)
- disable_dns_lookups (default: no)
- disable_mime_input_processing (default: no)
- disable_mime_output_conversion (default: no)
- disable_verp_bounces (default: no)
- disable_vrfy_command (default: no)
- dont_remove (default: 0)
- double_bounce_sender (default: double-bounce)
- duplicate_filter_limit (default: 1000)
- empty_address_recipient (default: MAILER-DAEMON)
- empty_address_relayhost_maps_lookup_key (default: <>)
- enable_errors_to (default: no)
- enable_original_recipient (default: yes)
- error_notice_recipient (default: postmaster)
- error_service_name (default: error)
- execution_directory_expansion_filter (default: see postconf -d output)
- expand_owner_alias (default: no)
- export_environment (default: see postconf -d output)
- extract_recipient_limit (default: 10240)
- fallback_relay (default: empty)
- fallback_transport (default: empty)
- fallback_transport_maps (default: empty)
- fast_flush_domains (default: $relay_domains)
- fast_flush_purge_time (default: 7d)
- fast_flush_refresh_time (default: 12h)
- fault_injection_code (default: 0)
- flush_service_name (default: flush)
- fork_attempts (default: 5)
- fork_delay (default: 1s)
- forward_expansion_filter (default: see postconf -d output)
- forward_path (default: see postconf -d output)
- frozen_delivered_to (default: yes)
- hash_queue_depth (default: 1)
- hash_queue_names (default: deferred, defer)
- header_address_token_limit (default: 10240)
- header_checks (default: empty)
- header_size_limit (default: 102400)
- helpful_warnings (default: yes)
- home_mailbox (default: empty)
- hopcount_limit (default: 50)
- html_directory (default: see postconf -d output)
- ignore_mx_lookup_error (default: no)
- import_environment (default: see postconf -d output)
- in_flow_delay (default: 1s)
- inet_interfaces (default: all)
- inet_protocols (default: ipv4)
- initial_destination_concurrency (default: 5)
- internal_mail_filter_classes (default: empty)
- invalid_hostname_reject_code (default: 501)
- ipc_idle (default: version dependent)
- ipc_timeout (default: 3600s)
- ipc_ttl (default: 1000s)
- line_length_limit (default: 2048)
- lmtp_assume_final (default: no)
- lmtp_bind_address (default: empty)
- lmtp_bind_address6 (default: empty)
- lmtp_cache_connection (default: yes)
- lmtp_cname_overrides_servername (default: yes)
- lmtp_connect_timeout (default: 0s)
- lmtp_connection_cache_destinations (default: empty)
- lmtp_connection_cache_on_demand (default: yes)
- lmtp_connection_cache_time_limit (default: 2s)
- lmtp_connection_reuse_time_limit (default: 300s)
- lmtp_data_done_timeout (default: 600s)
- lmtp_data_init_timeout (default: 120s)
- lmtp_data_xfer_timeout (default: 180s)
- lmtp_defer_if_no_mx_address_found (default: no)
- lmtp_destination_concurrency_limit (default: $default_destination_concurrency_limit)
- lmtp_destination_recipient_limit (default: $default_destination_recipient_limit)
- lmtp_discard_lhlo_keyword_address_maps (default: empty)
- lmtp_discard_lhlo_keywords (default: empty)
- lmtp_enforce_tls (default: no)
- lmtp_generic_maps (default: empty)
- lmtp_host_lookup (default: dns)
- lmtp_lhlo_name (default: $myhostname)
- lmtp_lhlo_timeout (default: 300s)
- lmtp_line_length_limit (default: 990)
- lmtp_mail_timeout (default: 300s)
- lmtp_mx_address_limit (default: 5)
- lmtp_mx_session_limit (default: 2)
- lmtp_pix_workaround_delay_time (default: 10s)
- lmtp_pix_workaround_maps (default: empty)
- lmtp_pix_workaround_threshold_time (default: 500s)
- lmtp_pix_workarounds (default: empty)
- lmtp_quit_timeout (default: 300s)
- lmtp_quote_rfc821_envelope (default: yes)
- lmtp_randomize_addresses (default: yes)
- lmtp_rcpt_timeout (default: 300s)
- lmtp_rset_timeout (default: 20s)
- lmtp_sasl_auth_cache_name (default: empty)
- lmtp_sasl_auth_cache_time (default: 90d)
- lmtp_sasl_auth_enable (default: no)
- lmtp_sasl_auth_soft_bounce (default: yes)
- lmtp_sasl_mechanism_filter (default: empty)
- lmtp_sasl_password_maps (default: empty)
- lmtp_sasl_path (default: empty)
- lmtp_sasl_security_options (default: noplaintext, noanonymous)
- lmtp_sasl_tls_security_options (default: $lmtp_sasl_security_options)
- lmtp_sasl_tls_verified_security_options (default: $lmtp_sasl_tls_security_options)
- lmtp_sasl_type (default: cyrus)
- lmtp_send_xforward_command (default: no)
- lmtp_sender_dependent_authentication (default: no)
- lmtp_skip_5xx_greeting (default: yes)
- lmtp_skip_quit_response (default: no)
- lmtp_starttls_timeout (default: 300s)
- lmtp_tcp_port (default: 24)
- lmtp_tls_CAfile (default: empty)
- lmtp_tls_CApath (default: empty)
- lmtp_tls_cert_file (default: empty)
- lmtp_tls_ciphers (default: export)
- lmtp_tls_dcert_file (default: empty)
- lmtp_tls_dkey_file (default: $lmtp_tls_dcert_file)
- lmtp_tls_eccert_file (default: empty)
- lmtp_tls_eckey_file (default: empty)
- lmtp_tls_enforce_peername (default: yes)
- lmtp_tls_exclude_ciphers (default: empty)
- lmtp_tls_fingerprint_cert_match (default: empty)
- lmtp_tls_fingerprint_digest (default: md5)
- lmtp_tls_key_file (default: $lmtp_tls_cert_file)
- lmtp_tls_loglevel (default: 0)
- lmtp_tls_mandatory_ciphers (default: empty)
- lmtp_tls_mandatory_exclude_ciphers (default: empty)
- lmtp_tls_mandatory_protocols (default: SSLv3, TLSv1)
- lmtp_tls_note_starttls_offer (default: no)
- lmtp_tls_per_site (default: empty)
- lmtp_tls_policy_maps (default: empty)
- lmtp_tls_protocols (default: empty)
- lmtp_tls_scert_verifydepth (default: 9)
- lmtp_tls_secure_cert_match (default: nexthop)
- lmtp_tls_security_level (default: empty)
- lmtp_tls_session_cache_database (default: empty)
- lmtp_tls_session_cache_timeout (default: 3600s)
- lmtp_tls_verify_cert_match (default: hostname)
- lmtp_use_tls (default: no)
- lmtp_xforward_timeout (default: 300s)
- local_command_shell (default: empty)
- local_destination_concurrency_limit (default: 2)
- local_destination_recipient_limit (default: 1)
- local_header_rewrite_clients (default: permit_inet_interfaces)
- local_recipient_maps (default: proxy:unix:passwd.byname $alias_maps)
- local_transport (default: local:$myhostname)
- luser_relay (default: empty)
- mail_name (default: Postfix)
- mail_owner (default: postfix)
- mail_release_date (default: see postconf -d output)
- mail_spool_directory (default: see postconf -d output)
- mail_version (default: see postconf -d output)
- mailbox_command (default: empty)
- mailbox_command_maps (default: empty)
- mailbox_delivery_lock (default: see postconf -d output)
- mailbox_size_limit (default: 51200000)
- mailbox_transport (default: empty)
- mailbox_transport_maps (default: empty)
- mailq_path (default: see postconf -d output)
- manpage_directory (default: see postconf -d output)
- maps_rbl_domains (default: empty)
- maps_rbl_reject_code (default: 554)
- masquerade_classes (default: envelope_sender, header_sender, header_recipient)
- masquerade_domains (default: empty)
- masquerade_exceptions (default: empty)
- master_service_disable (default: empty)
- max_idle (default: 100s)
- max_use (default: 100)
- maximal_backoff_time (default: 4000s)
- maximal_queue_lifetime (default: 5d)
- message_reject_characters (default: empty)
- message_size_limit (default: 10240000)
- message_strip_characters (default: empty)
- milter_command_timeout (default: 30s)
- milter_connect_macros (default: see postconf -d output)
- milter_connect_timeout (default: 30s)
- milter_content_timeout (default: 300s)
- milter_data_macros (default: see postconf -d output)
- milter_default_action (default: tempfail)
- milter_end_of_data_macros (default: see postconf -d output)
- milter_end_of_header_macros (default: see postconf -d output)
- milter_helo_macros (default: see postconf -d output)
- milter_macro_daemon_name (default: $myhostname)
- milter_macro_v (default: $mail_name $mail_version)
- milter_mail_macros (default: see postconf -d output)
- milter_protocol (default: 6)
- milter_rcpt_macros (default: see postconf -d output)
- milter_unknown_command_macros (default: see postconf -d output)
- mime_boundary_length_limit (default: 2048)
- mime_header_checks (default: $header_checks)
- mime_nesting_limit (default: 100)
- minimal_backoff_time (default: 300s)
- multi_instance_directories (default: empty)
- multi_instance_enable (default: no)
- multi_instance_group (default: empty)
- multi_instance_name (default: empty)
- multi_instance_wrapper (default: empty)
- multi_recipient_bounce_reject_code (default: 550)
- mydestination (default: $myhostname, localhost.$mydomain, localhost)
- mydomain (default: see postconf -d output)
- myhostname (default: see postconf -d output)
- mynetworks (default: see postconf -d output)
- mynetworks_style (default: subnet)
- myorigin (default: $myhostname)
- nested_header_checks (default: $header_checks)
- newaliases_path (default: see postconf -d output)
- non_fqdn_reject_code (default: 504)
- non_smtpd_milters (default: empty)
- notify_classes (default: resource, software)
- owner_request_special (default: yes)
- parent_domain_matches_subdomains (default: see postconf -d output)
- permit_mx_backup_networks (default: empty)
- pickup_service_name (default: pickup)
- plaintext_reject_code (default: 450)
- postmulti_control_commands (default: reload flush)
- postmulti_start_commands (default: start)
- postmulti_stop_commands (default: see postconf -d output)
- prepend_delivered_header (default: command, file, forward)
- process_id (read-only)
- process_id_directory (default: pid)
- process_name (read-only)
- propagate_unmatched_extensions (default: canonical, virtual)
- proxy_interfaces (default: empty)
- proxy_read_maps (default: see postconf -d output)
- proxy_write_maps (default: see postconf -d output)
- proxymap_service_name (default: proxymap)
- proxywrite_service_name (default: proxywrite)
- qmgr_clog_warn_time (default: 300s)
- qmgr_fudge_factor (default: 100)
- qmgr_message_active_limit (default: 20000)
- qmgr_message_recipient_limit (default: 20000)
- qmgr_message_recipient_minimum (default: 10)
- qmqpd_authorized_clients (default: empty)
- qmqpd_client_port_logging (default: no)
- qmqpd_error_delay (default: 1s)
- qmqpd_timeout (default: 300s)
- queue_directory (default: see postconf -d output)
- queue_file_attribute_count_limit (default: 100)
- queue_minfree (default: 0)
- queue_run_delay (default: 300s)
- queue_service_name (default: qmgr)
- rbl_reply_maps (default: empty)
- readme_directory (default: see postconf -d output)
- receive_override_options (default: empty)
- recipient_bcc_maps (default: empty)
- recipient_canonical_classes (default: envelope_recipient, header_recipient)
- recipient_canonical_maps (default: empty)
- recipient_delimiter (default: empty)
- reject_code (default: 554)
- reject_tempfail_action (default: defer_if_permit)
- relay_clientcerts (default: empty)
- relay_destination_concurrency_limit (default: $default_destination_concurrency_limit)
- relay_destination_recipient_limit (default: $default_destination_recipient_limit)
- relay_domains (default: $mydestination)
- relay_domains_reject_code (default: 554)
- relay_recipient_maps (default: empty)
- relay_transport (default: relay)
- relayhost (default: empty)
- relocated_maps (default: empty)
- remote_header_rewrite_domain (default: empty)
- require_home_directory (default: no)
- resolve_dequoted_address (default: yes)
- resolve_null_domain (default: no)
- resolve_numeric_domain (default: no)
- rewrite_service_name (default: rewrite)
- sample_directory (default: /etc/postfix)
- send_cyrus_sasl_authzid (default: no)
- sender_based_routing (default: no)
- sender_bcc_maps (default: empty)
- sender_canonical_classes (default: envelope_sender, header_sender)
- sender_canonical_maps (default: empty)
- sender_dependent_relayhost_maps (default: empty)
- sendmail_path (default: see postconf -d output)
- service_throttle_time (default: 60s)
- setgid_group (default: postdrop)
- show_user_unknown_table_name (default: yes)
- showq_service_name (default: showq)
- smtp_always_send_ehlo (default: yes)
- smtp_bind_address (default: empty)
- smtp_bind_address6 (default: empty)
- smtp_body_checks (default: empty)
- smtp_cname_overrides_servername (default: version dependent)
- smtp_connect_timeout (default: 30s)
- smtp_connection_cache_destinations (default: empty)
- smtp_connection_cache_on_demand (default: yes)
- smtp_connection_cache_reuse_limit (default: 10)
- smtp_connection_cache_time_limit (default: 2s)
- smtp_connection_reuse_time_limit (default: 300s)
- smtp_data_done_timeout (default: 600s)
- smtp_data_init_timeout (default: 120s)
- smtp_data_xfer_timeout (default: 180s)
- smtp_defer_if_no_mx_address_found (default: no)
- smtp_destination_concurrency_limit (default: $default_destination_concurrency_limit)
- smtp_destination_recipient_limit (default: $default_destination_recipient_limit)
- smtp_discard_ehlo_keyword_address_maps (default: empty)
- smtp_discard_ehlo_keywords (default: empty)
- smtp_enforce_tls (default: no)
- smtp_fallback_relay (default: $fallback_relay)
- smtp_generic_maps (default: empty)
- smtp_header_checks (default: empty)
- smtp_helo_name (default: $myhostname)
- smtp_helo_timeout (default: 300s)
- smtp_host_lookup (default: dns)
- smtp_line_length_limit (default: 990)
- smtp_mail_timeout (default: 300s)
- smtp_mime_header_checks (default: empty)
- smtp_mx_address_limit (default: 5)
- smtp_mx_session_limit (default: 2)
- smtp_nested_header_checks (default: empty)
- smtp_never_send_ehlo (default: no)
- smtp_pix_workaround_delay_time (default: 10s)
- smtp_pix_workaround_maps (default: empty)
- smtp_pix_workaround_threshold_time (default: 500s)
- smtp_pix_workarounds (default: disable_esmtp, delay_dotcrlf)
- smtp_quit_timeout (default: 300s)
- smtp_quote_rfc821_envelope (default: yes)
- smtp_randomize_addresses (default: yes)
- smtp_rcpt_timeout (default: 300s)
- smtp_rset_timeout (default: 20s)
- smtp_sasl_auth_cache_name (default: empty)
- smtp_sasl_auth_cache_time (default: 90d)
- smtp_sasl_auth_enable (default: no)
- smtp_sasl_auth_soft_bounce (default: yes)
- smtp_sasl_mechanism_filter (default: empty)
- smtp_sasl_password_maps (default: empty)
- smtp_sasl_path (default: empty)
- smtp_sasl_security_options (default: noplaintext, noanonymous)
- smtp_sasl_tls_security_options (default: $smtp_sasl_security_options)
- smtp_sasl_tls_verified_security_options (default: $smtp_sasl_tls_security_options)
- smtp_sasl_type (default: cyrus)
- smtp_send_xforward_command (default: no)
- smtp_sender_dependent_authentication (default: no)
- smtp_skip_4xx_greeting (default: yes)
- smtp_skip_5xx_greeting (default: yes)
- smtp_skip_quit_response (default: yes)
- smtp_starttls_timeout (default: 300s)
- smtp_tls_CAfile (default: empty)
- smtp_tls_CApath (default: empty)
- smtp_tls_cert_file (default: empty)
- smtp_tls_cipherlist (default: empty)
- smtp_tls_ciphers (default: export)
- smtp_tls_dcert_file (default: empty)
- smtp_tls_dkey_file (default: $smtp_tls_dcert_file)
- smtp_tls_eccert_file (default: empty)
- smtp_tls_eckey_file (default: $smtp_tls_eccert_file)
- smtp_tls_enforce_peername (default: yes)
- smtp_tls_exclude_ciphers (default: empty)
- smtp_tls_fingerprint_cert_match (default: empty)
- smtp_tls_fingerprint_digest (default: md5)
- smtp_tls_key_file (default: $smtp_tls_cert_file)
- smtp_tls_loglevel (default: 0)
- smtp_tls_mandatory_ciphers (default: medium)
- smtp_tls_mandatory_exclude_ciphers (default: empty)
- smtp_tls_mandatory_protocols (default: SSLv3, TLSv1)
- smtp_tls_note_starttls_offer (default: no)
- smtp_tls_per_site (default: empty)
- smtp_tls_policy_maps (default: empty)
- smtp_tls_protocols (default: !SSLv2)
- smtp_tls_scert_verifydepth (default: 9)
- smtp_tls_secure_cert_match (default: nexthop, dot-nexthop)
- smtp_tls_security_level (default: empty)
- smtp_tls_session_cache_database (default: empty)
- smtp_tls_session_cache_timeout (default: 3600s)
- smtp_tls_verify_cert_match (default: hostname)
- smtp_use_tls (default: no)
- smtp_xforward_timeout (default: 300s)
- smtpd_authorized_verp_clients (default: $authorized_verp_clients)
- smtpd_authorized_xclient_hosts (default: empty)
- smtpd_authorized_xforward_hosts (default: empty)
- smtpd_banner (default: $myhostname ESMTP $mail_name)
- smtpd_client_connection_count_limit (default: 50)
- smtpd_client_connection_rate_limit (default: 0)
- smtpd_client_event_limit_exceptions (default: $mynetworks)
- smtpd_client_message_rate_limit (default: 0)
- smtpd_client_new_tls_session_rate_limit (default: 0)
- smtpd_client_port_logging (default: no)
- smtpd_client_recipient_rate_limit (default: 0)
- smtpd_client_restrictions (default: empty)
- smtpd_data_restrictions (default: empty)
- smtpd_delay_open_until_valid_rcpt (default: yes)
- smtpd_delay_reject (default: yes)
- smtpd_discard_ehlo_keyword_address_maps (default: empty)
- smtpd_discard_ehlo_keywords (default: empty)
- smtpd_end_of_data_restrictions (default: empty)
- smtpd_enforce_tls (default: no)
- smtpd_error_sleep_time (default: 1s)
- smtpd_etrn_restrictions (default: empty)
- smtpd_expansion_filter (default: see postconf -d output)
- smtpd_forbidden_commands (default: CONNECT, GET, POST)
- smtpd_hard_error_limit (default: normal: 20, stress: 1)
- smtpd_helo_required (default: no)
- smtpd_helo_restrictions (default: empty)
- smtpd_history_flush_threshold (default: 100)
- smtpd_junk_command_limit (default: normal: 100, stress: 1)
- smtpd_milters (default: empty)
- smtpd_noop_commands (default: empty)
- smtpd_null_access_lookup_key (default: <>)
- smtpd_peername_lookup (default: yes)
- smtpd_policy_service_max_idle (default: 300s)
- smtpd_policy_service_max_ttl (default: 1000s)
- smtpd_policy_service_timeout (default: 100s)
- smtpd_proxy_ehlo (default: $myhostname)
- smtpd_proxy_filter (default: empty)
- smtpd_proxy_timeout (default: 100s)
- smtpd_recipient_limit (default: 1000)
- smtpd_recipient_overshoot_limit (default: 1000)
- smtpd_recipient_restrictions (default: permit_mynetworks, reject_unauth_destination)
- smtpd_reject_unlisted_recipient (default: yes)
- smtpd_reject_unlisted_sender (default: no)
- smtpd_restriction_classes (default: empty)
- smtpd_sasl_application_name (default: smtpd)
- smtpd_sasl_auth_enable (default: no)
- smtpd_sasl_authenticated_header (default: no)
- smtpd_sasl_exceptions_networks (default: empty)
- smtpd_sasl_local_domain (default: empty)
- smtpd_sasl_path (default: smtpd)
- smtpd_sasl_security_options (default: noanonymous)
- smtpd_sasl_tls_security_options (default: $smtpd_sasl_security_options)
- smtpd_sasl_type (default: cyrus)
- smtpd_sender_login_maps (default: empty)
- smtpd_sender_restrictions (default: empty)
- smtpd_soft_error_limit (default: 10)
- smtpd_starttls_timeout (default: 300s)
- smtpd_timeout (default: normal: 300s, stress: 10s)
- smtpd_tls_CAfile (default: empty)
- smtpd_tls_CApath (default: empty)
- smtpd_tls_always_issue_session_ids (default: yes)
- smtpd_tls_ask_ccert (default: no)
- smtpd_tls_auth_only (default: no)
- smtpd_tls_ccert_verifydepth (default: 9)
- smtpd_tls_cert_file (default: empty)
- smtpd_tls_cipherlist (default: empty)
- smtpd_tls_ciphers (default: export)
- smtpd_tls_dcert_file (default: empty)
- smtpd_tls_dh1024_param_file (default: empty)
- smtpd_tls_dh512_param_file (default: empty)
- smtpd_tls_dkey_file (default: $smtpd_tls_dcert_file)
- smtpd_tls_eccert_file (default: empty)
- smtpd_tls_eckey_file (default: $smtpd_tls_eccert_file)
- smtpd_tls_eecdh_grade (default: see postconf -d output)
- smtpd_tls_exclude_ciphers (default: empty)
- smtpd_tls_fingerprint_digest (default: md5)
- smtpd_tls_key_file (default: $smtpd_tls_cert_file)
- smtpd_tls_loglevel (default: 0)
- smtpd_tls_mandatory_ciphers (default: medium)
- smtpd_tls_mandatory_exclude_ciphers (default: empty)
- smtpd_tls_mandatory_protocols (default: SSLv3, TLSv1)
- smtpd_tls_protocols (default: empty)
- smtpd_tls_received_header (default: no)
- smtpd_tls_req_ccert (default: no)
- smtpd_tls_security_level (default: empty)
- smtpd_tls_session_cache_database (default: empty)
- smtpd_tls_session_cache_timeout (default: 3600s)
- smtpd_tls_wrappermode (default: no)
- smtpd_use_tls (default: no)
- soft_bounce (default: no)
- stale_lock_time (default: 500s)
- stress (default: empty)
- strict_7bit_headers (default: no)
- strict_8bitmime (default: no)
- strict_8bitmime_body (default: no)
- strict_mailbox_ownership (default: yes)
- strict_mime_encoding_domain (default: no)
- strict_rfc821_envelopes (default: no)
- sun_mailtool_compatibility (default: no)
- swap_bangpath (default: yes)
- syslog_facility (default: mail)
- syslog_name (default: see postconf -d output)
- tcp_windowsize (default: 0)
- tls_daemon_random_bytes (default: 32)
- tls_eecdh_strong_curve (default: prime256v1)
- tls_eecdh_ultra_curve (default: secp384r1)
- tls_export_cipherlist (default: ALL:+RC4:@STRENGTH)
- tls_high_cipherlist (default: ALL:!EXPORT:!LOW:!MEDIUM:+RC4:@STRENGTH)
- tls_low_cipherlist (default: ALL:!EXPORT:+RC4:@STRENGTH)
- tls_medium_cipherlist (default: ALL:!EXPORT:!LOW:+RC4:@STRENGTH)
- tls_null_cipherlist (default: eNULL:!aNULL)
- tls_random_bytes (default: 32)
- tls_random_exchange_name (default: see postconf -d output)
- tls_random_prng_update_period (default: 3600s)
- tls_random_reseed_period (default: 3600s)
- tls_random_source (default: see postconf -d output)
- trace_service_name (default: trace)
- transport_delivery_slot_cost (default: $default_delivery_slot_cost)
- transport_delivery_slot_discount (default: $default_delivery_slot_discount)
- transport_delivery_slot_loan (default: $default_delivery_slot_loan)
- transport_destination_concurrency_failed_cohort_limit (default: $default_destination_concurrency_failed_cohort_limit)
- transport_destination_concurrency_limit (default: $default_destination_concurrency_limit)
- transport_destination_concurrency_negative_feedback (default: $default_destination_concurrency_negative_feedback)
- transport_destination_concurrency_positive_feedback (default: $default_destination_concurrency_positive_feedback)
- transport_destination_rate_delay (default: $default_destination_rate_delay)
- transport_destination_recipient_limit (default: $default_destination_recipient_limit)
- transport_extra_recipient_limit (default: $default_extra_recipient_limit)
- transport_initial_destination_concurrency (default: $initial_destination_concurrency)
- transport_maps (default: empty)
- transport_minimum_delivery_slots (default: $default_minimum_delivery_slots)
- transport_recipient_limit (default: $default_recipient_limit)
- transport_recipient_refill_delay (default: $default_recipient_refill_delay)
- transport_recipient_refill_limit (default: $default_recipient_refill_limit)
- transport_retry_time (default: 60s)
- transport_time_limit (default: $command_time_limit)
- trigger_timeout (default: 10s)
- undisclosed_recipients_header (default: To: undisclosed-recipients:;)
- unknown_address_reject_code (default: 450)
- unknown_address_tempfail_action (default: $reject_tempfail_action)
- unknown_client_reject_code (default: 450)
- unknown_helo_hostname_tempfail_action (default: $reject_tempfail_action)
- unknown_hostname_reject_code (default: 450)
- unknown_local_recipient_reject_code (default: 550)
- unknown_relay_recipient_reject_code (default: 550)
- unknown_virtual_alias_reject_code (default: 550)
- unknown_virtual_mailbox_reject_code (default: 550)
- unverified_recipient_defer_code (default: 450)
- unverified_recipient_reject_code (default: 450)
- unverified_recipient_reject_reason (default: empty)
- unverified_recipient_tempfail_action (default: $reject_tempfail_action)
- unverified_sender_defer_code (default: 450)
- unverified_sender_reject_code (default: 450)
- unverified_sender_reject_reason (default: empty)
- unverified_sender_tempfail_action (default: $reject_tempfail_action)
- verp_delimiter_filter (default: -=+)
- virtual_alias_domains (default: $virtual_alias_maps)
- virtual_alias_expansion_limit (default: 1000)
- virtual_alias_maps (default: $virtual_maps)
- virtual_alias_recursion_limit (default: 1000)
- virtual_destination_concurrency_limit (default: $default_destination_concurrency_limit)
- virtual_destination_recipient_limit (default: $default_destination_recipient_limit)
- virtual_gid_maps (default: empty)
- virtual_mailbox_base (default: empty)
- virtual_mailbox_domains (default: $virtual_mailbox_maps)
- virtual_mailbox_limit (default: 51200000)
- virtual_mailbox_lock (default: see postconf -d output)
- virtual_mailbox_maps (default: empty)
- virtual_maps (default: empty)
- virtual_minimum_uid (default: 100)
- virtual_transport (default: virtual)
- virtual_uid_maps (default: empty)
- SEE ALSO
- LICENSE
- AUTHOR(S)
This document was created by man2html, using the manual pages.
Time: 05:34:00 GMT, December 24, 2015