Dmarcian report - DKIM fail

I have a question about dmarcian report about basic things i don’t understand.
Here is a screenshot of a report that I anonymized.
All IP in this screenshot all belong to my email service declare in the DNS.
there are things that I don’t understand : the three DKIM domains that don’t belong to me

I’m thinking of forwarded emails but according to SRS, the “Mail From” will be the Forwarder domain but here, this is always my domain so i don’t understand this.

Can you tell me which case can produce this result ?

Regards !

Hi kadmarc

There could be several reasons why you see a DKIM signing domain that doesn’t belong to you.

  • The email was forwarded automatically and the forwarding system signed the email.
  • The email came from a previous source and your environment forwarded it, and contains the original DKIM signature.
  • The email was sent by a third party and contains the third party’s DKIM signature

These are the main common scenarios, but there could be others. Regarding SRS, it does not always apply. SRS is not option that should apply in most cases, but not all environment are configured to use by default, and certain types of forwarding does not cause SRS to be employed, such as when emails are forwarded by Microsoft 365 within what they call a trust boundary.

The best way to answer your question would be for you to reach out to dmarcian support at The forums are community driven and are not meant for paying customers to use as technical support. This way, you can share more private account information with our support team to facilitate the investigation and provide you with a satisfactory response.

I hope this helps!