Linux Mail Server Setup and Howto Guide

Below are custom built Postfix RPM packages configured with enough options to support all the Postfix features described on this website. These packages are provided to save you time from building your own. The Postfix features enabled in these builds are LDAP, TLS, MySQL, SASL 2 and VDA.

SMTP Authentication (SMTP Auth) provides an access control mechanism that can be used to allow legitimate users to relay mail while denying relay service to unauthorized users, such as spammers.

Postgrey is a simple and powerful anti-spam tool for Postfix. It works by using a technique called Greylisting. Adding greylisting in Postfix will give your Postfix mail server a simple and effective first line of defense against spam, at a cost of a few minor delays for newly identified senders.

By default, Postfix listens on the SMTP port number 25. Some ISPs block this port number so you may wish to provide an alternate port number to listen to or change it altogether.

If your Postfix mail server has multiple IP addresses, it will use the same SMTP hostname greeting on every IP Address. This may cause a problem since some mail servers check the SMTP hostname banner to see if the hostname points to the same mail server. If not, any mail you send may be rejected or handled as spam. You can confirm if you have this problem by getting a DNS report on your domain name.

This guide will show you how to integrate Active Directory/LDAP into Postfix and Dovecot. In this page, you will learn how to enable Postfix to lookup email addresses in LDAP and how to enable Dovecot to authenticate to an LDAP server.

This page will guide you in configuring MailScanner, ClamAV and SpamAssassin to work in Postfix. Before proceeding, please make sure that all of the above components are already installed.

Installing and setting up Postfix SMTP Server in Red Hat Enterprise Linux 5 or CentOS 5 is easy. Postfix has secure default settings so we just need to open it up a bit.

Enabling SMTP authentication in Postfix ensures that only users with valid accounts can send email outside your network (relaying). This prevents spammers from using your SMTP server as a spam broadcast station. Here’s how to do it in Postfix.

Active Directory has a type of grouping called Distribution group used solely as an email distribution list. This page will show you how to use the distribution group as a mailing list for Postfix. But first, you need to upgrade Postfix to version 2.4 or higher. Download Postfix RPM Packages.