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DKIM Record Lookup

Look up DKIM public key records for a domain and selector. Verify your DKIM DNS configuration.

Common: default, google, k1, selector1

About DKIM Record Lookup

DKIM (DomainKeys Identified Mail) is an email authentication standard that lets a domain owner sign outgoing messages with a private key. Receiving mail servers verify the signature by retrieving the public key from a DNS TXT record and checking it against the signature in the email header. A valid signature proves the email genuinely came from an authorised sender and was not modified in transit.

DKIM record structure

DKIM public keys are published as TXT records at {selector}._domainkey.{domain}. The record contains key-value pairs separated by semicolons:

  • v=DKIM1 — Version (always DKIM1)
  • k=rsa — Key type (RSA is standard; ed25519 is newer and more compact)
  • p=... — The Base64-encoded public key
  • t=s — Flags (e.g. s restricts the key to email only)

Finding your DKIM selector

The selector identifies which key was used to sign a message. Each sending service or mail server has its own selector. Common selectors include:

  • Google Workspace — google
  • Microsoft 365 — selector1, selector2
  • Mailchimp / Mandrill — k1
  • Others — default, mail, dkim

To find the selector used by a specific email, view the raw email headers and look for the DKIM-Signature header — the s= tag contains the selector.

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Frequently asked questions

What is a DKIM selector?
A DKIM selector is a label used to identify which DKIM key pair was used to sign a message. Common selectors include "default", "google", "k1", "mail", "dkim", "selector1", "selector2" (Microsoft 365). You can find the selector in the DKIM-Signature header of a sent email.
Where is the DKIM record stored?
DKIM records are stored as TXT records at {selector}._domainkey.{domain}. For example, for selector "default" and domain "example.com" the lookup is default._domainkey.example.com.