Attachment blocking with spoofed addresses and DMARC

[A. Schulze]

Benny Pedersen:

> why accept dmarc fail ?
Quanah did not mention the real domain so it's possible they publish a  
policy p=none.
Than no reject will happen in any case.

@Quanah
Maybe there is a setting "mydomains" including "domain.com" and an  
other setting "warn_banned_file_sender"
(not checked what the real parameter names are ...)
As the external message claim to be internal that would trigger that  
behaviour.

Do your customer use the same amavis instance for submission an inbound MX?
Then "warn_banned_file_sender" should be enabled only on a policy bank  
dedicated to submission.

Andreas