DMARC
Domain-based Message Authentication, Reporting and Conformance
A DNS entry that tells recipients’ mailboxes what to do with an email from your domain that fails the SPF or DKIM check: deliver it, move it to spam or reject it.
Where should you start with DMARC?
Google recommends starting with a relaxed policy: emails are delivered as before, and the domain owner receives reports. A stricter policy comes later, once you know that legitimate emails pass the check.
When should you add DMARC?
Only after SPF and DKIM are set up. Google recommends waiting 48 hours after turning them on, otherwise email delivery problems may occur.
Category: Security