DMARC record explainer

Paste a record such as v=DMARC1; p=none; rua=mailto:dmarc@example.com to see what it tells mail providers to do.

Which policy should a small business use?

Start with p=none and a rua address for a few weeks to see who sends email for the domain. Once every legitimate sender passes, move to p=quarantine and then p=reject. Staying on p=none forever leaves the domain open to spoofing.