DKIM_KEY_MISMATCH

error

A valid DKIM key is published here, but it is not the one we issued. It may be left over from another provider.

Something is wrong and mail or certificates are affected.

How we know

dkim.test
DKIM semantics as distinct from wire-level mangling: revoked (empty p=), a real 512-bit key, testing mode, wrong version, v= not first, unsupported algorithm, and a non-DKIM TXT sharing the selector. Every key is real and parses with node:crypto.