DMARC adkim — DKIM alignment mode
How closely the DKIM signing domain must match the From: domain.
- Required
- no
- Default
- r
- Valid values
r (relaxed) | s (strict)
What it does
Relaxed (the default) accepts any subdomain: a signature from mail.example.com aligns with From: example.com. Strict requires an exact match. Strict alignment breaks most third-party senders, which sign with their own subdomain of your domain, so leave this relaxed unless you have a specific reason.
Example
v=DMARC1; p=reject; adkim=s; aspf=s; rua=mailto:dmarc@example.com