Information on how to configure and debug sendmail problems including common configuration questions, understanding sendmail rules and rulesets, and using debug flags and address test mode.

Completed Harker’s Helpful Hints

Adding Rules To Any Ruleset When Using M4

Including A Quick Reference Guide To The sendmail Metasymbols

Configure sendmail for HELO check

Message-ID Headers From Non-Local SMTP Clients

Understanding Sendmail Address Rewriting Rules

How To Configure sendmail For Dial On Demand Operation

How to use only submit.cf on a sendmail SMTP client

Delivering Mail To Sendmail On Different Ports Using SMTP

Requeuing Mail For Problem Domains Or Hosts That Are Down

Limiting Maximum Message Size For Selected Users

Configuring sendmail to receive mail for your domain

Subject: archival/compliance/etc

Bouncing mail for invalid users

Using "env_sender $| env_rcpt" check_compat rules in the check_rcpt ruleset

How do I see how sendmail will deliver a message?

sendmail options to check re-wrting of domain

How to use address test mode and how to understand its output

Force queue on individual email

How to bouce mail for users with no forwarding address