Free tool

SPF and DMARC check

Type a domain. See its SPF, DMARC, DKIM and mail server records in plain English, and the exact record to add if something is missing.

Free, no signup. Reads public records only, nothing is stored.

What the results mean

SPF: A list of the services allowed to send email for your domain. One record per domain, and no more than 10 DNS lookups.
DMARC: Tells inboxes what to do with mail that fails SPF and DKIM, and where to send reports. Start with p=none, then move to quarantine.
DKIM: A signature that proves the message was not changed in transit. Your email provider gives you the record to publish.
MX: The servers that receive mail for your domain. Without them, replies bounce.

DNS is one part of deliverability.

Domains, warmup, daily caps, list hygiene and the legal basics are in the free checklist.