ZeroTrust with attachments in MS 365

[Kyrouz]

How can we declare permitted Internet email attachment types while blocking the rest?

[#2]

@Kyrouz 

Follow below if you would like to manage under your own tenant:

https://learn.microsoft.com/en-us/exchange/security-and-compliance/mail-flow-rules/common-attachment...

[#3]

That article describes different scenarios using blocklists. How do I create a rule to specifically allow authorized attachment types and not allow anything else? None of the actions in the Rule Conditions say "Deliver the message as normal".