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Postfix MTA by Wietse Venema
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Latest commit fd122dd Wietse Venema committed with Viktor Dukhovni postfix-3.1-20151031
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Purpose of this document

This document provides a road map of the Postfix mail system source
code distribution.  I suggest that you

- take a few minutes to read this file,

- review the RELEASE_NOTES file for incompatible changes,

- and then proceed with the INSTALL instructions.


This is the public release of the Postfix mail system. Thank you
for your interest in this project. Send me a postcard if you like
it. My postal address is below.

You must read the LICENSE file, if you didn't do so already. A copy
of the LICENSE must be distributed with every original, modified,
complete, source, or binary copy of this software or parts thereof.
I suggest that you keep a copy of the file in /etc/postfix/LICENSE.

Purpose of the Postfix mail system

Postfix aims to be an alternative to the widely-used sendmail

Although IBM supported the Postfix development, it abstains from
control over its evolution. The goal is to have Postfix installed
on as many systems as possible. To this end, the software is given
away with no strings attached to it, so that it can evolve with
input from and under control by its users.

In other words, IBM releases Postfix only once. I will be around
to guide its development for a limited time.

On-line resources devoted to the Postfix mail system

Web sites:		current release information

Mail addresses (PLEASE send questions to the mailing list)		Postfix users mailing list

In order to subscribe to the mailing list, see


This release could not have happened without the input from a team
of competent alpha testers. Their names appear in numerous places
in the HISTORY file. I appreciate the input from my colleagues at
the IBM Global Security Analysis Laboratory:  Paul Karger, Dave
Safford, Douglas Schales, and Leendert van Doorn.  I also appreciate
the support by Charles Palmer under whose leadership I began this
project, and who had the privilege to name the software, twice.

If you wish to express your appreciation for the Postfix software,
you are welcome to send a postcard to:

	Wietse Venema
	IBM T.J Watson Research Center
	P.O. Box 704, 
	Yorktown Heights, NY 10598

Roadmap of the Postfix source distribution

The RELEASE_NOTES file describes new features, and lists incompatible
changes with respect to previous Postfix versions.

The INSTALL file provides a step-by-step guide for building and
installing Postfix on many popular UNIX platforms.

The COMPATIBILITY file lists features that Postfix does or does
not yet implement, and how well it works with other software.

The HISTORY file gives a detailed log of changes to the software.

Point your browser at html/index.html for Postfix documentation
and for hyperlinked versions of Postfix manual pages.  Expect
to see updated versions on-line at

Point your MANPATH environment variable at the `man' directory (use
an absolute path) for UNIX-style on-line manual pages.  These pages
are also available through the HTML interface, which allows you to
navigate faster.

The PORTING file discusses how to go about porting Postfix to other
UNIX platforms.


    README_FILES/	Instructions for specific Postfix features
    html/		HTML format
    man/		UNIX on-line manual page format

Example files:

    conf/		configuration files, run-time scripts
    examples/		chroot environments, virtual domains

Library routines:

    src/dns/		DNS client library
    src/global/		Postfix-specific support routines
    src/milter/		Postfix Milter (mail filter) client
    src/tls/		TLS client and server support
    src/util/		General-purpose support routines
    src/xsasl/		SASL plug-in API

Command-line utilities:

    src/postalias/	Alias database management
    src/postcat/	List Postfix queue file
    src/postconf/	Configuration utility
    src/postdrop/	Postfix mail submission program
    src/postfix/	Postfix administrative interface
    src/postkick/	Postfix IPC for shell scripts
    src/postlock/	Postfix locking for shell scripts
    src/postlog/	Postfix logging for shell scripts
    src/postmap/	Postfix lookup table management
    src/postmulti/	Postfix multi-instance manager
    src/postqueue/	Postfix queue control program
    src/postsuper/	Postfix house keeping program
    src/sendmail/	Sendmail compatibility interface

Postfix daemons:

    src/anvil/		Connection count/rate limiter
    src/bounce/		Bounce or defer mail
    src/cleanup/	Canonicalize and enqueue mail
    src/discard/	Trivial discard mailer
    src/dnsblog/	DNS agent for postscreen
    src/error/		Trivial error mailer
    src/flush/		Support for ETRN, sendmail -qI, sendmail -qR
    src/local/		Local delivery
    src/master/		Postfix resident superserver
    src/oqmgr/		Old queue manager
    src/pickup/		Local pickup
    src/pipe/		Pipe delivery
    src/postscreen/	Zombie blocker
    src/proxymap/	Table lookup proxy agent
    src/qmgr/		Queue manager
    src/qmqpd/		QMQPD server
    src/scache/		Postfix SMTP session cache
    src/showq/		List Postfix queue status
    src/smtp/		SMTP and LMTP client
    src/smtpd/		SMTP server
    src/spawn/		Run non-Postfix server
    src/tlsmgr/		TLS session keys and random pool
    src/tlsproxy/	TLS proxy for postscreen
    src/trivial-rewrite/ Address rewriting and resolving
    src/verify/		address verification service
    src/virtual/	virtual mailbox-only delivery agent

Test programs:

    src/fsstone/	Measure file system overhead
    src/posttls-finger/	Postfix SMTP/LMTP TLS probe utility
    src/smtpstone/	SMTP and QMQP server torture test


    auxiliary/		Auxiliary software etc.
    bin/		Postfix command executables
    conf/		Configuration files, run-time scripts
    include/		Include files
    implementation-notes/ Background information
    lib/		Object libraries
    libexec/		Postfix daemon executables
    mantools/		Documentation utilities
    proto/		Documentation source
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