What file type violated the transport rule in Exchange? #M365AMA

In this episode, the #M365AMA panel discusses the following community question:

“I know that an email violated a transport rule for bad attachments, but I cannot determine what file type actually violated the rule. Extended Report offers no insight, and message headers do not include this information. Without a Defender license, how can I gain further insight into what was the violating file type?”

Check out the discussion here:

 

Participating in this discussion were:

• Christian Buckley, RD+MVP @buckleyplanet 
• Heather Severino, MVP+MCT @HeatherSeverino
• Hal Hostetler, MVP  @TVWizard
• Kirsty McGrath, MVP @KirstyMcGrath13
• Mike Nelson, MVP  @mikenelsonIO

Some relevant notes/links shared by the team:

• How to Tell Which Transport Rule Was Applied to an Email Message, via Paul Cunningham at Practical 365 [https://practical365.com/tell-transport-rule-applied-email-message/]
• Mail flow rules (transport rules) in Exchange Online, via Microsoft Learn [https://learn.microsoft.com/en-us/exchange/security-and-compliance/mail-flow-rules/mail-flow-rules]