Postfix and OpenDKIM Integration
Sign outbound messages with DKIM using a local milter.
Production note: Back up configuration, run
postfix check, and stage changes before reloading.Postfix milter settings
milter_default_action = accept
milter_protocol = 6
smtpd_milters = inet:127.0.0.1:8891
non_smtpd_milters = inet:127.0.0.1:8891OpenDKIM tables
Use KeyTable, SigningTable, and TrustedHosts to select keys by domain and control trusted injection sources.
DNS publication
Publish the selector TXT record and validate it before enabling signing for production traffic.
Verify signatures
opendkim-testkey -d example.com -s s1 -vvv