Network tool
DKIM Checker
Look up the DKIM public-key record published for a domain and selector.
What this result means
DKIM publishes a public key in DNS so receiving mail systems can verify signatures on individual messages. A published record alone does not prove messages are signed or authenticated correctly.
How this check works
This check queries selector._domainkey.domain for a TXT record. It follows at most two valid public CNAME targets, does not contact any mailbox, and does not send or inspect email messages.
Organizations can publish several selectors, and there is no universal selector to guess. Get the selector from the mail provider or domain administrator before treating a missing record as a problem.