The mail server does not sign outgoing letters, where to dig?

Question

postfix

I do everything according to the manual (not the first time already)
But the service https://www.mail-tester.com/ stubbornly says that the letters do not have a signature (rating 7.7 out of 10),
There are no errors in the postfix logs, the brain has already broken - where could I be wrong?

Answer 1

I could make a mistake anywhere, offhand:

• opendkim is not running
  
• Opendkim has no rights to the private key
  
• Public key in DNS published with errors