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-rw-r--r--man/man8/smtp.899
1 files changed, 62 insertions, 37 deletions
diff --git a/man/man8/smtp.8 b/man/man8/smtp.8
index e53a377..0145350 100644
--- a/man/man8/smtp.8
+++ b/man/man8/smtp.8
@@ -1,14 +1,16 @@
-.TH SMTP 8
+.TH SMTP, LMTP 8
.ad
.fi
.SH NAME
-smtp
+smtp, lmtp
\-
Postfix SMTP+LMTP client
.SH "SYNOPSIS"
.na
.nf
\fBsmtp\fR [generic Postfix daemon options] [flags=DORX]
+
+\fBlmtp\fR [generic Postfix daemon options] [flags=DORX]
.SH DESCRIPTION
.ad
.fi
@@ -17,7 +19,9 @@ delivery protocols. It processes message delivery requests from
the queue manager. Each request specifies a queue file, a sender
address, a domain or host to deliver to, and recipient information.
This program expects to be run from the \fBmaster\fR(8) process
-manager.
+manager. The process name, \fBsmtp\fR or \fBlmtp\fR, controls
+the protocol, and the names of the configuration parameters
+that will be used.
The SMTP+LMTP client updates the queue file and marks recipients
as finished, or it informs the queue manager that delivery should
@@ -25,13 +29,9 @@ be tried again at a later time. Delivery status reports are sent
to the \fBbounce\fR(8), \fBdefer\fR(8) or \fBtrace\fR(8) daemon as
appropriate.
-The SMTP+LMTP client looks up a list of mail exchanger addresses for
-the destination host, sorts the list by preference, and connects
-to each listed address until it finds a server that responds.
-
-When a server is not reachable, or when mail delivery fails due
-to a recoverable error condition, the SMTP+LMTP client will try to
-deliver the mail to an alternate host.
+The server lookup strategy is different for SMTP and LMTP,
+as described in the sections "SMTP SERVER LOOKUP" and "LMTP
+SERVER LOOKUP".
After a successful mail transaction, a connection may be saved
to the \fBscache\fR(8) connection cache server, so that it
@@ -41,48 +41,62 @@ By default, connection caching is enabled temporarily for
destinations that have a high volume of mail in the active
queue. Connection caching can be enabled permanently for
specific destinations.
-.SH "SMTP DESTINATION SYNTAX"
+.SH "SMTP SERVER LOOKUP"
.na
.nf
.ad
.fi
-The Postfix SMTP+LMTP client supports multiple destinations
+The Postfix SMTP client supports multiple destinations
separated by comma or whitespace (Postfix 3.5 and later).
+Each destination is tried in the specified order.
+
SMTP destinations have the following form:
.IP \fIdomainname\fR
-.IP \fIdomainname\fR:\fIport\fR
+.IP \fIdomainname\fR:\fIservice\fR
Look up the mail exchangers for the specified domain, and
-connect to the specified port (default: \fBsmtp\fR).
+connect to the specified service (default: \fBsmtp\fR).
+Optionally, mail exchangers may be looked up with SRV queries
+instead of MX; this requires that \fIservice\fR is given
+in symbolic form.
.IP [\fIhostname\fR]
-.IP [\fIhostname\fR]:\fIport\fR
-Look up the address(es) of the specified host, and connect to
-the specified port (default: \fBsmtp\fR).
+.IP [\fIhostname\fR]:\fIservice\fR
+Look up the address(es) for the specified host, and connect to
+the specified service (default: \fBsmtp\fR).
.IP [\fIaddress\fR]
-.IP [\fIaddress\fR]:\fIport\fR
+.IP [\fIaddress\fR]:\fIservice\fR
Connect to the host at the specified address, and connect
-to the specified port (default: \fBsmtp\fR). An IPv6 address
+to the specified service (default: \fBsmtp\fR). An IPv6 address
must be formatted as [\fBipv6\fR:\fIaddress\fR].
-.SH "LMTP DESTINATION SYNTAX"
+.SH "LMTP SERVER LOOKUP"
.na
.nf
.ad
.fi
-The Postfix SMTP+LMTP client supports multiple destinations
+The Postfix LMTP client supports multiple destinations
separated by comma or whitespace (Postfix 3.5 and later).
+Each destination is tried in the specified order.
+
LMTP destinations have the following form:
.IP \fBunix\fR:\fIpathname\fR
Connect to the local UNIX\-domain server that is bound to the specified
\fIpathname\fR. If the process runs chrooted, an absolute pathname
is interpreted relative to the Postfix queue directory.
+.IP \fBinet\fR:\fIdomainname\fR
+.IP \fBinet\fR:\fIdomainname\fR:\fIservice\fR
+Look up the LMTP servers for the specified domain and service
+(default: \fBlmtp\fR).
+This form is supported when SRV lookups are enabled, and
+requires that \fIservice\fR is in symbolic form.
.IP \fBinet\fR:\fIhostname\fR
-.IP \fBinet\fR:\fIhostname\fR:\fIport\fR
+.IP \fBinet\fR:\fIhostname\fR:\fIservice\fR
+Look up the address(es) for the specified host, and connect to
+the specified service (default: \fBlmtp\fR). When SRV lookups
+are enabled, use the form \fB[\fIhostname\fB]\fR to force
+address lookups.
.IP \fBinet\fR:[\fIaddress\fR]
-.IP \fBinet\fR:[\fIaddress\fR]:\fIport\fR
-Connect to the specified TCP port on the specified local or
-remote host. If no port is specified, connect to the port defined as
-\fBlmtp\fR in \fBservices\fR(4).
-If no such service is found, the \fBlmtp_tcp_port\fR configuration
-parameter (default value of 24) will be used.
+.IP \fBinet\fR:[\fIaddress\fR]:\fIservice\fR
+Connect to the specified local or remote host and service
+(default: \fBlmtp\fR).
An IPv6 address must be formatted as [\fBipv6\fR:\fIaddress\fR].
.SH "SINGLE-RECIPIENT DELIVERY"
.na
@@ -146,6 +160,8 @@ This feature is available as of Postfix 3.5.
.SH "SECURITY"
.na
.nf
+.ad
+.fi
The SMTP+LMTP client is moderately security\-sensitive. It
talks to SMTP or LMTP servers and to DNS servers on the
network. The SMTP+LMTP client can be run chrooted at fixed
@@ -199,11 +215,10 @@ address and TCP port.
.nf
.ad
.fi
-Before Postfix version 2.3, the LMTP client is a separate
-program that implements only a subset of the functionality
-available with SMTP: there is no support for TLS, and
-connections are cached in\-process, making it ineffective
-when the client is used for multiple domains.
+Postfix versions 2.3 and later implement the SMTP and LMTP
+client with the same program, and choose the protocol and
+configuration parameters based on the process name, \fBsmtp\fR
+or \fBlmtp\fR.
Most smtp_\fIxxx\fR configuration parameters have an
lmtp_\fIxxx\fR "mirror" parameter for the equivalent LMTP
@@ -464,6 +479,11 @@ Available in Postfix version 2.9 and later:
.IP "\fBsmtp_send_dummy_mail_auth (no)\fR"
Whether or not to append the "AUTH=<>" option to the MAIL
FROM command in SASL\-authenticated SMTP sessions.
+.PP
+Available in Postfix version 3.9 and later:
+.IP "\fBsmtp_sasl_password_result_delimiter (:)\fR"
+The delimiter between username and password in sasl_passwd_maps lookup
+results.
.SH "STARTTLS SUPPORT CONTROLS"
.na
.nf
@@ -566,7 +586,7 @@ The message digest algorithm used to construct remote SMTP server
certificate fingerprints.
.PP
Available in Postfix version 2.6 and later:
-.IP "\fBsmtp_tls_protocols (see postconf -d output)\fR"
+.IP "\fBsmtp_tls_protocols (see 'postconf -d' output)\fR"
TLS protocols that the Postfix SMTP client will use with
opportunistic TLS encryption.
.IP "\fBsmtp_tls_ciphers (medium)\fR"
@@ -647,6 +667,11 @@ Optional configuration file with baseline OpenSSL settings.
.IP "\fBtls_config_name (empty)\fR"
The application name passed by Postfix to OpenSSL library
initialization functions.
+.PP
+Available in Postfix version 3.9 and later:
+.IP "\fBsmtp_tls_enable_rpk (no)\fR"
+Request that remote SMTP servers send an RFC7250 raw public key
+instead of an X.509 certificate.
.SH "OBSOLETE STARTTLS CONTROLS"
.na
.nf
@@ -843,9 +868,9 @@ sub\-second delay values.
.IP "\fBdisable_dns_lookups (no)\fR"
Disable DNS lookups in the Postfix SMTP and LMTP clients.
.IP "\fBinet_interfaces (all)\fR"
-The local network interface addresses that this mail system receives
-mail on.
-.IP "\fBinet_protocols (see 'postconf -d output')\fR"
+The local network interface addresses that this mail system
+receives mail on.
+.IP "\fBinet_protocols (see 'postconf -d' output)\fR"
The Internet protocols Postfix will attempt to use when making
or accepting connections.
.IP "\fBipc_timeout (3600s)\fR"