Postfix Overview - Introduction - SCN Research

SMTP(8)
SMTP(8)
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NAME
smtp - Postfix remote delivery via SMTP
SYNOPSIS
smtp [generic Postfix daemon options]
DESCRIPTION
The SMTP client 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
master(8) process manager.
The SMTP client updates the queue file and marks recipients
as finished, or it informs the queue manager that
delivery should be tried again at a later time. Delivery
problem reports are sent to the bounce(8) or defer(8) daemon
as appropriate.
The SMTP 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 the domain or host is specified as a comma/whitespace
separated list, the SMTP client repeats the above process
for all destinations until it finds a server that
responds.
Once the SMTP client has received the server greeting banner,
no error will cause it to proceed to the next address
on the mail exchanger list. Instead, the message is either
bounced, or its delivery is deferred until later.
SECURITY
The SMTP client is moderately security-sensitive. It talks
to SMTP servers and to DNS servers on the network. The
SMTP client can be run chrooted at fixed low privilege.
STANDARDS
RFC 821 (SMTP protocol)
RFC 1651 (SMTP service extensions)
RFC 1870 (Message Size Declaration)
RFC 2197 (Pipelining)
RFC 2554 (AUTH command)
RFC 2821 (SMTP protocol)
DIAGNOSTICS
Problems and transactions are logged to syslogd(8). Corrupted
message files are marked so that the queue manager
can move them to the corrupt queue for further inspection.
Depending on the setting of the notify_classes parameter,
the postmaster is notified of bounces, protocol problems,
and of other trouble.
BUGS
CONFIGURATION PARAMETERS
The following main.cf parameters are especially relevant
to this program. See the Postfix main.cf file for syntax
details and for default values. Use the postfix reload
http://www.porcupine.org/postfix-mirror/smtp.8.html
6/26/01