Linux Mail Server Setup and Howto Guide

This page will show you how to join your Linux server into the Active Directory domain, how to integrate the Active Directory user accounts into the Linux user accounts and how to authenticate users in Active Directory using Winbind, a component of Samba.

Samba is installed by default when you select the Server installation type during the installation process. In case you need to install or reinstall it, just select the Windows File Server package in the Package Management tool.

Setup and Configure Winbind

1. Click Applications, select System Settings and click Authentication. This will launch the Authentication Configuration window.

Red Hat Enterprise Linux 4 and its derivative CentOS 4 includes a graphical tool called Security Level Configuration for configuring the firewall options. This guide describes how to use this tool to open up the ports necessary for providing an email server.

1. Click Applications, select System Settings and click Security Level. This will launch the Security Level Configuration window.

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.

Here are the installation guides for the above components.

• How to install Postfix SMTP Server
• How to install Clam Anti-virus (ClamAV)
• How to install MailScanner

SpamAssassin is included in CentOS 4 and ready to go out of the box. Just add it using the Package Management tool if you haven’t done so during CentOS installation. SpamAssassin is located in the Mail Server package.

Configuring MailScanner

1. Edit the file /etc/MailScanner/MailScanner.conf

To install MailScanner, we are going to download the latest source code from the MailScanner web site and build it. For this to work, it needs the Development Tools package. If you did not include this during installation, you must add it now. Learn how to add or remove applications here.

Getting MailScanner

1. Click the globe icon at the top near the Actions menu to launch the Firefox web browser.

 

If an error occurs, you probably did not install the Graphical Internet package. You can add it now using the Package Management tool.

To install Clam AntiVirus (ClamAV), we are going to use the precompiled binaries from Dag Wieers RPM packages for Red Hat, RHEL, CentOS and Fedora. To do this, we are going to configure Yum to look for the ClamAV packages in Dag’s repository.

Adding Dag Wieers RPM Repository to Yum

1. Click Applications, select System Tools and click Terminal. This will launch the Terminal window. Type in the command cd /etc/yum.repos.d and press Enter. This will bring us to the Yum repository configuration directory.

In Linux, new user accounts automatically receive mail accounts. Here are the steps for adding new users in Red Hat Enterprise Linux 4 or CentOS 4.

1. Click Applications then select System Settings and click Users and Groups. This will launch the User Manager window.

SquirrelMail is an open source standards-based webmail package written in PHP. When installed, SquirrelMail is ready out of the box. All it needs is an installed web server like Apache, SMTP server like Postfix, and IMAP server like Dovecot.

Here are the installation guides for Postfix and Dovecot.

• How to install Postfix SMTP Server
• How to install Dovecot POP3 and IMAP Server

Starting the Web Server

1. If you did not add Web Server and squirrelmail during the CentOS installation, you can add it now. Using the Package Management tool, add the Web Server package. Also add squirrelmail located inside the Mail Server package.

Installing and setting up Dovecot in RHEL 4 or CentOS 4 is easy. All we have to do is to enable the services we would like to provide and we are good to go.

Install Dovecot

1. If you did not add dovecot during the CentOS installation, you can add it now. Dovecot is located in the package Mail Server. Learn how to add or remove applications here.

Installing and setting up Postfix SMTP Server in RHEL 4 or CentOS 4 is easy. Postfix has secure default settings so we just need to open it up a bit.

Install Postfix and Mail Transport Agent Switcher

1. If you did not add postfix and system-switch-mail-gnome during the CentOS installation, you can add it now. Postfix is located in the package Mail Server while system-switch-mail-gnome is in X Windows System. Learn how to add or remove applications here.

Red Hat Enterprise Linux 4 and its derivative CentOS 4 includes an extensive list of applications that can be easily added or removed. This guide will show you how to do it using the Package Management tool.

1. Click Applications, select System Settings and click Add/Remove Applications. This will launch the Package Management window.