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 ...

Reducing Syslogd Performance Issues Syslogd is the main logging program for many Linux systems.  Unfortunately it can cause performance issues by using synchronous writes by default.  If you open syslog.conf you will see that the mail logging goes to /var/log/mail.log.  In order to prevent synchronous writes a "-" is placed in front of the log. mail.*                          -/var/log/mail.log This is a default on most ...

Thunderbird, Icedove if you are on Debian is an excellent choice for an email client especially as it is capable of connecting using SSL or TLS and SMTP AUTH.  Many email clients are not able to do that.  Why TLS, well it is all about encrypting your password and data when you connect to your mail server.  In addition, when you use SMTP AUTH, you can travel and your mail server will allow you to send email because you have authenticated. Create ...