Postscreen Basics
Reduce abusive SMTP connection load before handing clients to smtpd.
Production note: Back up configuration, run
postfix check, and stage changes before reloading.Role
Postscreen performs lightweight checks on inbound port 25 clients. It is not used for authenticated submission.
Conservative baseline
postscreen_greet_action = enforce
postscreen_dnsbl_action = ignore
postscreen_pipelining_enable = yes
postscreen_non_smtp_command_enable = yesAllowlisting
Maintain explicit allowlists for trusted infrastructure and avoid relying blindly on external DNSBLs.
Monitor
Start in observe/ignore modes where applicable and review logs before enforcement.