DMARC

This plugin requires the Perl Module Mail::DMARC.

This plugin checks if emails match DMARC policy using the SPF and DKIM verification results. The plugin needs both the DKIM and SPF plugins enabled. It requires the Mail::DMARC Perl module and is only available on SpamAssassin 4.0 or newer.

How it works

The plugin looks up the DMARC policy (the p= tag) published for the author's domain and checks how it aligns with the message's SPF and DKIM authentication. Depending on the policy and alignment it fires one of the DMARC_PASS, DMARC_REJECT, DMARC_QUAR, or DMARC_NONE rules, or DMARC_MISSING when no DMARC policy record is found for the domain.

Rules

When a rule lists four scores: the first applies when neither the Bayesian classifier nor network tests are in use, the second when only network tests are in use, the third when only the Bayesian classifier is in use and the fourth when both are in use.

Area Rule name Description Default scores
header DMARC_PASS DMARC pass policy -0.001
header DMARC_REJECT DMARC reject policy 0.001 1.797 0.001 1.797
header DMARC_QUAR DMARC quarantine policy 0.001 1.198 0.001 1.198
header DMARC_NONE DMARC none policy 0.001 0.898 0.001 0.898
header DMARC_MISSING Missing DMARC policy 0.001

Settings

This plugin has no additional settings. It can be enabled or disabled under Warden -> Settings -> Plugin Settings -> DMARC. It is only available on SpamAssassin 4.0 or newer.