DKIM Checker

Run DKIM Checker using the supplied input and options.

Unicode text; preserve input unless the selected operation changes it.

Your workbenchInputs are not stored

Result

Enter your values and run the tool to see your result.

What this tool does

Looks up a DKIM public key record from a domain and selector. With DKIM, the sending server signs the message and the receiver verifies that signature against the public key in DNS.

How to use it

  1. Enter the domain.
  2. Enter the selector — you can read it from the s= value in a message’s DKIM-Signature header.
  3. Run it to see the lookup result for selector._domainkey.domain.

Worked example

Domain example.com with selector default looks up default._domainkey.example.com.

Frequently asked questions

How do I find the selector?
Open the raw headers of a message from that domain and read the s= value in the DKIM-Signature line. Your mail provider’s DKIM settings page also lists it.
Can there be several selectors?
Yes. Each sending path usually has its own selector, so check them one at a time.

What this tool does not cover

It only confirms the public key record and its contents. Whether a given signature actually validates — or breaks because the body was altered — requires inspecting a real message.

References