Filtering E-Mail with Postfix and Procmail, Part Two

by Brian Hatch Sept. 1, 2017 via Symantec

This article is the second of three articles that will help systems administrators configure SMTP daemons and local mail delivery agents to filter out unwanted e-mails before they arrive in the end-users' in-box. In the first installment, we offered a brief overview of Postfix, and began a discussion of rejecting spam with Postfix by blocking e-mail based on the SMTP client, blocking machines with no reverse DNS, SMTP client map restrictions, DNS blackhole lists, bundling Postfix restriction options, and blocking spam based on SMTP Compliance. In this part, we will look at sender/recipient restrictions, restriction ordering, and map file naming conventions before moving on to Procmail in the final article.