Posts tagged: dmarcbis
DMARC Subdomain Policy: sp= and np= Explained
DMARC subdomain policy sets how subdomains inherit p=, sp=, and np=. See the DMARCbis tree walk, sp= vs np=, and how to stop non-existent-subdomain spoofing.
How to Create a DMARC Record: Tags, Examples & Setup
How to create a DMARC record step by step — tags, syntax, real examples, and the p=none → p=reject rollout. Verify it with a free DMARC checker.
RFC 9989 DMARC: What Changed From RFC 7489
RFC 9989 replaces RFC 7489 as DMARC's Standards-Track spec (May 2026). What changed: the RFC 9990 aggregate / 9991 failure split, tree walk, pct removed.