0

I am under heavy attack by the infamous hacker extortion scam. I am hardening the security of my mail server as I run my own Postfix on cloud.

Today I have stumbled upon this evidence in my logs:

dkimproxy.in[123584]: DKIM verify - none; message-id=<20190515@example.org>, from=<user@example.org> 

This email claims to come from my own address, as part of the scam's scheme. I am surprised that dkimproxy sets none as verification result for mail coming from my own example.org, because that domain has a policy. It should have failed miserably

I have just used this tool to confirm that my selector is active. I also used nslookup type txt to ping for selector._domainkey.example.org from the Postfix box self and it returned my key.

Question: why is dkimproxy not failing (epically? miserably?) for email that clearly show a forged sender? The email itself does obviously not report any DKIM header. It was my understanding that when a DKIM policy demands mail to be authenticated, mail servers should quarantine/reject those messages according to the policy self.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.