About EmailMonitor
Free, standards-based tools for checking and monitoring email authentication.
EmailMonitor makes it easy to see whether a domain's email authentication is set up correctly, and to find out quickly when it stops being correct.
What we build
- Checkers for SPF, DKIM, DMARC, MX, BIMI, MTA-STS and TLS-RPT that query public DNS live and validate records against the relevant RFCs.
- Generators that produce valid SPF, DMARC, DKIM and BIMI records. DKIM key pairs are generated in your browser.
- Free daily monitoring that re-checks your domain and emails you when something changes.
How the checks work
When you run a check, our servers send DNS-over-HTTPS queries to Cloudflare's 1.1.1.1 resolver, falling back to Google Public DNS, and parse the answers. For MTA-STS we also fetch the policy file over HTTPS. Results reflect what those resolvers return at that moment; recent DNS changes may take time to propagate.
Independence
Some guide and comparison pages may contain affiliate links to email tools. Those links never change check results, and we say so on any page that has them.
Questions or corrections? Contact us.