Forum Discussion
DMARC hacked bypassed with empty header.from or only semicolon
WRAP UP On the 26th of September 2024 an email was delivered to one of our Exchange Online mailboxes from the Internet through EOP that spoofes one of our accepted domains although this domain is pr...
To me it appears like that "Non-compliant RFC 5322 P2 FROM header detection" in "November 2024 Exchange Server Security Updates" partly addresses my issue. However transport rules would still be needed in order to Honor DMARC. Furthermore it's not clear to me yet, if those transport rules had consequences on emails passing DMARC though detected by this mechanism.
Released: November 2024 Exchange Server Security Updates | Microsoft Community Hubhttps://techcommunity.microsoft.com/blog/exchange/released-november-2024-exchange-server-security-updates/4293125