Linux E-mail

System-wide rules

Now that we have covered all the basics of setting up rules, analyzing e-mails, and generally seeing how all of the processing operations interact, we will look through a couple of examples for system-wide filtering, testing, and operations.

Removing executables

In Chapter 9, we will see how to integrate a complete virus checking system into the Postfix mail architecture. This will perform accurate virus signature recognition and add suitable flags to the mail headers to indicate if a virus is present in the mail. However, if it is not possible to set up such a system, this rule will provide an alternative but more brutal approach to block all e-mails with executable attachments.

If you place the following in /etc/procmailrc