A DKIM selector identifies which public key to use in DNS. Learn how selectors work and best practices for rotation.
A DKIM selector is a label that points to the correct public key in DNS for verifying a DKIM signature. It allows a domain to publish multiple DKIM keys at the same time.
Selectors make key rotation easier: you can publish a new selector, start signing with it, and retire old ones safely. Keeping selectors organized and documented avoids verification failures.