Practical tools for mail records, sender authentication, message headers and DMARC reports. Choose a tool to open its dedicated page. Headers and report files are processed locally; DNS checks query public resolvers.
DKIM checker
Inspect the public signing key for a domain and selector.
Open tool →DMARC lookup
Read a domain’s DMARC policy, reporting settings and alignment tags.
Open tool →DMARC report viewer
Explore aggregate DMARC reports, source addresses and authentication results locally.
Open tool →E-mail header analyser
Inspect message routing, delivery delays and reported authentication results.
Open tool →Microsoft 365 DNS checker
Check public DNS records used by a commercial Microsoft 365 mail setup.
Open tool →MX lookup
Find a domain’s incoming mail servers and their priorities.
Open tool →SPF analyser
Expand SPF includes and redirects and identify policy issues.
Open tool →SPF lookup
Read the SPF policy published in a domain’s TXT records.
Open tool →For general DNS records, propagation, domain registration and reverse DNS, visit DNS Tools →.