Forum Discussion

Copper Contributor

May 24, 2020

Solved

MIME in Office ATP

Hi all, I have a customer that is migrating from a 3rd party email gateway solution to Office ATP P2. One thing that has come up that has stumped me is the 3rd party solution is able to block via...

security

VasilMichev
May 25, 2020
It does check based on content, not just on file extension as detailed for example here: https://docs.microsoft.com/en-us/exchange/security-and-compliance/mail-flow-rules/inspect-message-attachments#supported-file-types-for-mail-flow-rule-content-inspection

Or check the description of the common attachment types filter feature.

You cannot add custom mime types if that's what you're after, but you can add custom extensions.

VasilMichev

MVP

May 25, 2020

It does check based on content, not just on file extension as detailed for example here: https://docs.microsoft.com/en-us/exchange/security-and-compliance/mail-flow-rules/inspect-message-attachments#supported-file-types-for-mail-flow-rule-content-inspection

Or check the description of the common attachment types filter feature.

You cannot add custom mime types if that's what you're after, but you can add custom extensions.