Securing the PostfixAdmin Directory on Ubuntu Many administrators who use Postfixadmin, a web based tool to manage virtual domains on Postfix, would like to secure the transactions between the PostfixAdmin program and the administrator.  At the same time often you do not want to add the extra burden of SSL on the whole domain but just want to secure one directory.   The solution is to create a certificate for that one directory only and also locking ...

What do you do when you massive overload of unwanted mail that is coming to your server?  Recently I saw a Postfix Mail server that had gone down some months ago but had 10s of thousands of email ready to  be sent.  When it was repaired it began sending tons of old mail....mail that was simply not needed to send any longer. This is a ...

Blacklists are a little easier to understand in that you will find domains or senders that you simply do not want to receive mail from them ever. There are two blacklist directives.  The first directive, blacklist_from will specify a a sender address that address is what will appear in the Resent-From, From, Envelope-Sender, Resent-Sender or X-Envelope-From. When the sender address matches a score of 100 is added to the sender, which effectively blocks ...

Global Manual Whitelist Once you have set up Spamassassin so it is working and you have run it for some time you may want to tune it to provide automatic whitelists and blacklists.  The whitelist will provide a way to insure that the mail from a particular source will never get rejected.  This may be important clients, users on the system or messages from servers that do not necessarily have the right credentials for sending mail. Your company may have ...

Install and Configure the Vacation Option This installation is for Ubuntu 9.10 but should work for just about any Linux distro.  The vacation package is nice in that you can create an automatic message for when you are not available. You will need to install a number of packages. sudo apt-get install libmail-sender-perl ...

PostfixAdmin provides a way to manage your virtual accounts, multiple domains, using a web based interface.  Once it is set up it is very easy to use.  This install process is not easy to do as there are many commands and a lot of configuration that must be done without mistakes.  If you would like a Live Virtual Class for Postfix, ...

Learning System You are able to additionally tune SpamAssassin to learn about your email.  Two programs are used together to create this learning system; autowhitelisting and Bayesian filtering.  Autowhitelisting is an algorithm that learns about each senders history and modifies the spam score of their subsequent mail.  This should ...

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 ...