Depending on your preferences, tagging messages as spam may not be enough. Maybe you'll want to set up a rule in your e-mail client that moves any unwanted messages from your inbox to a dedicated spam directory. Or maybe you want such routing to happen automatically on the server. We can configure this using Procmail, a mail filtering and delivery agent.
In this recipe, we'll look at how to configure Procmail to route messages. We'll scan incoming mail, looking for a special header that SpamAssassin adds to messages if it thinks they're spam and then deliver them to a separate directory instead of the inbox.
This recipe requires a CentOS system with Postfix configured as described in the previous recipes. Administrative privileges are also required, either by logging in with the root account or through the use of sudo.