Get full access to sendmail, 4th Edition and 60K+ other titles, with a free 10-day trial of O'Reilly.

There are also live events, courses curated by job role, and more.

Chapter 20. The M (Mail Delivery Agent) Configuration Command

Other than relaying mail via SMTP or LMTP, the sendmail program does not perform the actual delivery of mail.^[268] Instead, it calls other programs (called mail delivery agents) to perform that service. Because the mechanics of delivery can vary so widely from delivery agent to delivery agent, sendmail needs a great deal of information about each delivery agent. Each sendmail M configuration command defines a mail delivery agent and the information that sendmail needs.

^[268]^* For the purpose of this discussion, we gloss over the fact that sendmail actually can deliver directly to files (Delivery to Files on page 466).

Get sendmail, 4th Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial

Don’t leave empty-handed

Get Mark Richards’s Software Architecture Patterns ebook to better understand how to design components—and how they should interact.

It’s yours, free.

Get it now

Check it out now on O’Reilly

Dive in for free with a 10-day trial of the O’Reilly learning platform—then explore all the other resources our members count on to build skills and solve problems every day.

Start your free trial Become a member now