Hey Jim,
I'm having the same issue with spoofed emails using the FROM in the P2 header, so I decided to kill them by removing the ms-exch-smtp-accept-authoritative-domain-sender permissions on my receive connector. But now UTM is not able to send Quarantine reports, as UTM sends the reports to that receive connector using one of our email addresses and Exchange is rejecting them now.
How are you handling the Quarantine reports after changing those permissions on the Exchange receive connector?
Thanks!
I have SPF enabled on UTM and have SPF records set up for my domain. The thing is UTM uses SPF to check only the MAIL FROM field on the P1 headers of an email. Emails can still be spoofed by altering the FROM field on the P2 headers of an email. Unfortunately, UTM does not check P2 headers of emails, thus allowing spoofed emails to still come through.
I have SPF enabled on UTM and have SPF records set up for my domain. The thing is UTM uses SPF to check only the MAIL FROM field on the P1 headers of an email. Emails can still be spoofed by altering the FROM field on the P2 headers of an email. Unfortunately, UTM does not check P2 headers of emails, thus allowing spoofed emails to still come through.