DMARC explained
DMARC: what receivers do with mail that fails
DMARC tells receivers what to do when a message fails SPF and DKIM for your domain, and where to send reports.
Where it lives
One TXT record at _dmarc on your domain.
_dmarc v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.comWhat to know
Gmail and Yahoo expect it
Since February 2024 both require a DMARC record from anyone sending them mail in bulk.
Start at p=none
None only collects reports. Move to quarantine, then reject, once the reports are clean.
Alignment matters
SPF or DKIM must pass for the same domain as your From address, not just any domain.
Common mistakes
- No DMARC record at all
- Jumping straight to p=reject and losing real mail
- Sending reports to an inbox nobody reads