Free tools

Free email authentication checkers

Look up any domain's DNS records for DMARC, SPF, DKIM and MTA-STS. Each tool gives a plain-English verdict and the raw record, with no sign-up.

DMARC checker

Does the domain publish DMARC, and is its policy actually stopping impersonation?

Is there an SPF record, and is it within the 10-lookup limit before it breaks?

Does a DKIM key exist at a given selector, and how strong is it?

Is inbound mail required to use TLS, and does the policy still match the real MX?

Not sure where to start? The DMARC checker gives the fullest overview of a domain. To understand what any of these records do, read what is DMARC or follow the path to p=reject.