Sometimes when you are working with Postfix you may be on an older version that does not support a feature you need.  Here is a list of the version and the major features that were added for that version. Postfix 2.5 Stress-dependent configuration Postfix 2.3 DKIM, DomainKeys and SenderID authentication, DSN status notifications, Enhanced status codes, Plug-in support for multiple SASL implementations (Cyrus, Dovecot), Configurable delivery status ...

The postcont -n command for Postfix shows you changes made to the default configuration.  Here is a listing of the new Ubuntu 9.10 and the output for Postfix.  As you can see nothing too significant except you see a focus on TLS for secure communication which is great, however this really needs to be addressed for users from the client ...

Recently we asked administrators why they used Postfix Mail Server.  Here are some of the responses: "Being able to manage users and pretty much all mail aspects from a MySQL table" "Security.  Postfix is rock solid and I do not have to worry about the security of the system once it is set up correctly" "Flexibility!" "I've been running Postfix on an array of servers for the last eight years.  I don't think I'd ever switch to anything ...

One of the newest features of Ubuntu 9.04 is the Postfix Mail Server/Dovecot enhancements to make it easier to set up a mail server.  This article is a review of those improvements and a tutorial on how to fix several problems that were experienced. Before you jump to any conclusions about the new features it is important to ...

The notify_classes allows you to send mail reports to the postmaster.  This is additional information that is not usually reported because only the worst situations are typically reported.  Here is a list of the notify_classes that you can use.  The default for Postfix is to use resource and software. bounce – This option will ...

Deferred  queue If Postfix cannot deliver a message to a recipient it is placed in the deferred queue.  The queue manager will scan the deferred queue to see it if can place mail back into the active queue.  How often this scan occurs is determined by the queue_run_delay.  Postfix will scan the incoming queue at the same time as the ...

You can list the default settings with Postfix with this command: postconf -d 2bounce_notice_recipient = postmaster access_map_reject_code = 554 address_verify_default_transport = $default_transport address_verify_local_transport = $local_transport address_verify_map = address_verify_negative_cache = yes address_verify_negative_expire_time = 3d address_verify_negative_refresh_time = 3h address_verify_poll_count = 3 address_verify_poll_delay ...

Understanding the mail queues, what they do and how they work are important steps to Postfix configuration.  Here are the queues listed with a summary of what they do and where they are located. Incoming The incoming queue is the location a message is sent once it has entered the system through SMTP or qmqpd  and then was sent to the cleanup service.  The cleanup service will provide the last evaluation of email before it is queued.  The cleanup ...