Linux Mail Server Setup and Howto Guide

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

%org-name% = your organization name
%org-long-name% = your full organization name
Run As User = postfix
Run As Group = postfix
Incoming Queue Dir = /var/spool/postfix/hold
Outgoing Queue Dir = /var/spool/postfix/incoming
MTA = postfix
Virus Scanners = clamd
Clamd Socket = /tmp/clamd.socket
Use SpamAssassin = yes
SpamAssassin User State Dir = /var/spool/MailScanner/spamassassin

2. Click Applications and click File Browser to launch the File Browser window and go to the /var/spool/MailScanner directory.

3. In the File Browser window, click File and click Create Folder. Name the new folder spamassassin.

4. Right click on the folder incoming and click Properties.

5. In the Properties window, click the Permissions tab. In the Permissions page, set the File owner as postfix, the File group as postfix and check only the Owner Read, Write and Execute. Click Close when you are done. Repeat this for the quarantine and spamassassin folders.

Integrating MailScanner into Postfix

1. Edit the file /etc/postfix/main.cf and remove the # in front of the line below

header_checks = regexp:/etc/postfix/header_checks

2. Edit the file /etc/postfix/header_checks and add the line below to the bottom of the file

/^Received:/ HOLD

This will now place all incoming mail into the holding area until released by MailScanner.

3. MailScanner should now be the one to start the Postfix service. Stop the Postfix service and start the MailScanner service in that order. Learn how to stop and start services here.

4. Test if Postfix is still working. See Test Postfix using Telnet.

Congratulations

Congratulations, your mails are now checked for spam and viruses. Each mail you send or receive will now contain the lines below to indicate that MailScanner is doing its job.

This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

***
Posted on 3/14/2007 and last updated on 3/24/2008
Filed under Anti-spam/Anti-virus , CentOS 4 , MailScanner , Postfix , Red Hat Enterprise Linux 4