DKIM selector
The selector tells receivers which DNS name contains the public DKIM key.
Common selectors include default, mail,
selector1 and google.
Email · DNS · DKIM
DKIM check
Check a domain’s DKIM selector and public DKIM key from DNS. DKIM helps verify that an email message was sent by an authorized system and was not modified in transit.
A DKIM record is usually published as
selector._domainkey.example.com. Common selectors include
default, mail, selector1,
selector2 and google.
Enter a domain and DKIM selector.
Guide · DKIM and email signatures
What does this DKIM check do?
The DKIM check shows whether a public DKIM key has been published in DNS for
the selected domain and selector. A DKIM record is usually published under
selector._domainkey.example.com.
DKIM adds a cryptographic signature to outgoing email. The receiving mail server can verify that signature using the public key published in DNS. This helps confirm that the message has not been changed in transit and that the signature is connected to the domain.
Public key
The public key is the p= value in the DKIM record. Receivers
use it to verify the DKIM signature of the message.
Key type
The key type is often shown with the k=rsa tag. It describes
the type of key used for the DKIM signature.
DMARC connection
DKIM is an important part of DMARC. If DKIM passes and aligns correctly, DMARC can accept the message based on DKIM.
Why does DKIM matter?
DKIM improves email trust because the receiver can verify that a message was signed with a key approved by the domain. This helps reduce forged email and supports better deliverability.
DKIM is especially useful together with SPF and DMARC. SPF defines where email may be sent from, DKIM signs messages and DMARC tells receivers what to do when authentication checks fail.
How to interpret the result
A good DKIM result means that one clear DKIM record was found for the selected selector and that the record contains a public key. If no record is found, the selector may be wrong or DKIM may not be enabled for the domain.
If the public key is missing or looks unusually short, the DKIM setup should be checked in the email service settings. Some services also use multiple selectors, for example for different sending systems or key rotation.
Frequently asked questions
How do I know the correct DKIM selector?
The DKIM selector is usually shown in the email service or sending platform
settings. Common selectors include default, mail,
selector1, selector2 and google.
Can a domain have multiple DKIM selectors?
Yes. A domain can have multiple DKIM selectors for different email services, marketing platforms or key rotation.
Do I need DKIM if SPF is already enabled?
Yes. DKIM should be used alongside SPF. SPF and DKIM check different things, and DMARC works best when both are configured correctly.