DMARC (Domain-based Message Authentication, Reporting and Conformance) tells receivers what to do when a message fails SPF and DKIM alignment, and asks them to send aggregate and forensic reports back to the domain owner.
What is DMARC alignment?
The domain in the visible From header must match (exactly or organizationally) the domain that passed SPF or DKIM. Set adkim=s and aspf=s for strict matching.
How long until I can reach p=reject?
Typically 4 to 12 weeks depending on how many third-party senders you have to fix.
What are RUA and RUF reports?
RUA are daily aggregate XML reports of pass/fail counts per source. RUF are per-message forensic samples; many receivers no longer send them.
Why does DMARC policies matter for deliverability?
DMARC at p=reject is what actually stops exact-domain spoofing. Gmail and Yahoo require at least p=none for bulk senders, and BIMI requires p=quarantine or p=reject.
What is the first step to get started with DMARC policies?
Confirm SPF and DKIM are deployed and aligned for every legitimate sender.
What is the most common DMARC policies mistake?
Jumping straight to p=reject and blocking your own invoicing or HR system.