DMARC Shark

Free DMARC checker for your domain

Check DMARC, SPF and email DNS records. Add known DKIM selectors when needed. Free, with no account or test emails.

Start a fresh check

Which domain should we look at?

Only check a selector you already know. You can enter up to two, separated by commas.
Checks <selector>._bimi.<domain>. Leave blank for the default selector.

Fresh checks only when you ask. Published records are not proof that a particular email will authenticate or reach an inbox.

Building an integration? Explore the JSON API and MCP tools →

Troubleshoot DMARC, SPF and DKIM findings →

01 / SPF

Who may send?

Shows published authorization for the SMTP envelope sender. It does not validate every sending service.

02 / DMARC

What policy applies?

Finds the policy for the visible From domain, including inherited policies for subdomains.

03 / MX + DANE + TLS-RPT + MTA-STS + DKIM + BIMI

Where's the evidence?

Displays inbound routing or an explicit Null MX, bounded DANE/TLSA evidence for advertised mail exchangers, published TLS reporting and MTA-STS transport policy, an optional DKIM selector's key, the default or supplied BIMI assertion record, and the resolver's DNSSEC validation evidence.