Managing DMARC across many domains means protecting the ones you don’t send from too — parked and subsidiary domains are prime spoofing targets. Centralize reporting, apply a baseline policy to every domain (including a strict record on non-sending domains), and enforce in waves.
A domain that never sends mail should still publish DMARC at p=reject plus a restrictive SPF (v=spf1 -all) — otherwise attackers can spoof it freely. Parked domains are the most overlooked risk in a portfolio.
Use one dashboard for all domains, a consistent rua reporting destination, and a standard policy baseline. Then enforce in waves, highest-risk/highest-volume domains first.
Publish a reject policy and a null SPF:
$ v=DMARC1; p=reject; rua=mailto:[email protected]Check your DMARC record now
Open the free DMARC checker →Yes — set them to p=reject with v=spf1 -all. They send no mail, so enforcement carries no risk and closes a common spoofing gap.
