DMARC aspf — SPF alignment mode
How closely the SPF domain must match the From: domain.
- Required
- no
- Default
- r
- Valid values
r (relaxed) | s (strict)
What it does
DMARC does not care whether SPF passed — it cares whether SPF passed for a domain that aligns with the visible From: address. Relaxed allows subdomains; strict demands an exact match. Strict aspf commonly breaks mail sent through providers that use their own bounce domain.
Example
v=DMARC1; p=quarantine; aspf=s; rua=mailto:dmarc@example.com