What Is a DKIM Selector?

Understand DKIM selectors and how they point receivers to the right public signing key.

Selector plus domain equals a DNS name

A DKIM selector is a label chosen by the sender. Receivers combine it with _domainkey and the signing domain.

For example, selector google on example.com becomes google._domainkey.example.com.

Providers can publish a new selector before retiring an old one. That keeps signed mail valid during rotation.

If a selector lookup fails, check the provider instructions and make sure the TXT record is published exactly.

Recommended next steps

Turn this guide into a concrete DNS report for your own domain.

Generate SPF and DMARC records before publishing DNS changes.

Look up a DKIM selector record and inspect the public key published for a domain.

Paste raw email headers to inspect routing hops, authentication results, and message metadata.

Yes. Different services often use different selectors for the same domain.

No. The selector is visible in email headers and points to a public DNS record.