Difference between revisions of "Postfix"

Latest revision as of 16:00, 17 September 2021

About

Postfix is an open source mail transfer agent (MTA) for POSIX systems. It is fully supported by Webmin/VirtualMin and is part of the Dovecot stack.

Pages

/aliasing: managing email redirects/aliases
/fixing: diagnosis of installations that aren't working right
see also: DKIM, DMARC, Sender Policy Framework (SPF)
/chroot: running Postfix in a chrooted environment

Files

/main.cf
/master.cf: formatted list of transport helper applications
/mail.log (typically found in /var/log)

Internal Apps

User Applets

/newaliases

Other Applets

These are installed as part of the postfix package; not sure how they should be classified:

/usr/bin:
- /mailq
- /newaliases - user utility
- /rmail
/usr/lib:
- /postfix_groups.pl
- /sendmail

/usr/lib/postfix:
- /anvil
- /bounce
- /cleanup
- /discard
- /error
- /flush
- /fsstone
- /lmtp
- /local
- /master
- /oqmgr
- /pickup
- /pipe
- /post-install
- /postfix-files
- /postfix-script
- /postfix-wrapper
- /postmulti-script
- /proxymap
- /qmgr
- /qmqpd
- /scache
- /showq
- /smtp
- /smtpd
- /spawn
- /tlsmgr
- /trivial-rewrite
- /verify
- /virtual

/usr/sbin:
- /postalias
- /postcat
- /postconf
- /postdrop
- /postfix - core binary
- /postfix-add-filter
- /postfix-add-policy
- /postkick
- /postlock
- /postlog
- /postmap
- /postmulti
- /postqueue
- /postsuper
- /qmqp-sink
- /qmqp-source
- /qshape
- /rmail
- /sendmail
- /smtp-sink
- /smtp-source

Error Messages

Other Subpages

/flow: the flow of messages across the various helper programs that make up Postfix
/SSL: Postfix and SSL

Notes

After making changes to the Postfix configuration files, you don't actually have to stop and restart Postfix to load the changes; you can just type (as root) "postfix reload".

automatic BCC

To automatically BCC outgoing mail from any given set of users, set sender_bcc_maps in /main.cf to hash:/etc/postfix/sender_bcc. (In Webmin: BCC Mapping: Sender BCC mapping lookup tables)

Each line in the /sender_bcc file will contain the sender (which can be user@domain, user, or @domain), one or more blanks, then the recipient (which can be one address or multiple addresses separated by commas).

Example -- BCCs all mail sent by vbz.com users to an archive address:

@vbz.com archive2024@vbz.com

pages to index

Possibly useful pages:

Setting Up Postfix As A Backup MX
Postfix Address Rewriting
trivial-rewrite (manpage)
Postfix Configuration Parameters (includes /main.cf parameters)
Postfix After-Queue Content Filter
Group-Office Mailserver plugin: helps administer Postfix
Mail server using Postfix and Dovecot on Gentoo Linux

Links

Official

Reference

Wikipedia

@@ Line 10: / Line 10: @@
 [[Postfix]] is an [[open source]] [[mail transfer agent]] (MTA) for [[POSIX]] systems. It is fully supported by [[Webmin]]/[[VirtualMin]] and is part of the [[Dovecot]] stack.
 ===Pages===
+* [[/aliasing]]: managing email redirects/aliases
 * [[/fixing]]: diagnosis of installations that aren't working right
+* see also: [[DKIM]], [[DMARC]], [[Sender Policy Framework]] (SPF)
+* [[/chroot]]: running Postfix in a [[chroot]]ed environment
 ===Files===
 * [[/main.cf]]
@@ Line 103: / Line 107: @@
 * [[/flow]]: the flow of messages across the various helper programs that make up Postfix
 * [[/SSL]]: Postfix and SSL
 ==Notes==
 After making changes to the Postfix configuration files, you don't actually have to stop and restart Postfix to load the changes; you can just type (as root) "postfix reload".
-===aliases===
-To set up aliases, either edit the file specified by the [[/main.cf/alias_maps|alias_maps]] setting in [[/main.cf|main.cf]] ([[etc/aliases|/etc/aliases]] by default) and then run [[newaliases]] (or "postalias /etc/aliases") to update the database, or else use [[Webmin]] ("Mail Aliases" icon, then click on the "Create a new alias" link).
-There is also a <code>/etc/postfix/virtual</code> file for aliases in virtual domains.
-'''Notes''':
-* Webmin seems to automatically run newaliases when you add or modify an individual alias, but ''not'' when you use it to edit the [[etc/aliases|/etc/aliases]] file directly. Changes made to /etc/aliases will not take effect until the database is updated.
-* Stopping and starting the postfix daemon does ''not'' update from the aliases file; you still have to run newaliases.
-* see [http://www.postfix.org/aliases.5.html aliases] for more information.
-===virtual users===
-By default, virtual aliases seem to get looked up only when email comes from the outside; locally generated emails are "returned" as undeliverable with the error message "Diagnostic-Code: x-unix; user unknown"
-The following change in main.cf solves that problem &ndash;
-* '''change''': {{link/subpage|pfx=/main.cf/|receive_override_options}} = no_address_mappings
-* '''to this''': receive_override_options =
-&ndash; but creates a new one, in that externally-sourced messages are now delivered ''twice'' (or ''four'' times if addressed directly to a virtual user instead of a virtual alias).
-Someone who understands the internal structure of postfix could probably figure out what this means (and how to fix it), but I'm still working on it.
-===catch-all===
-To set up a catch-all address, edit {{link/subpage|main.cf}} and set the following parameters:
-* {{link/subpage|pfx=/main.cf/|local_recipient_maps}} =
-* {{link/subpage|pfx=/main.cf/|luser_relay}} = <u>whereToSend</u>
-The syntax for <u>whereToSend</u> is explained [http://www.postfix.org/postconf.5.html#luser_relay here].
-Examples:
-* luser_relay = $user@anotherdomain.org
-** forwards all email addressed to "invaliduser@firstdomain.org" to "invaliduser@anotherdomain.org"
-* luser_relay = youraddress@anotherdomain.org
-** forwards all email addressed to invalid users to "youraddress@anotherdomain.org".
-[http://www.cyberciti.biz/faq/howto-setup-postfix-catch-all-email-accounts/ This page] mentions some other parameters but neglects the ones above.
 ===automatic BCC===