marking emails as internal vs external when using mass mail provider

Copper Contributor

Hi folks !

 

In our tenant, we have activated a rule that warns users when received emails are from an external source, and this works quite well. However, we have departments that use external mass mail providers (like mailchimp) to reach out to both internal and external recipients. Is there some way I could construct a rule that would trust specific internal email addresses as being internal even when they are received from an external source and not trigger the external email rule ? Obviously this would require specifying the sender organisation in some way...

 

Am I making any sense ? :)

 

2 Replies
you can add exclusion in your transport rule if the email sent by the specific email address and also you can add the specific email header from the value to exclusion in transport rule.
You can either use a transport rule to mark the traffic from this source as trusted, or user Enhanced filtering for connectors:

https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/use-connectors-to-configure-mail-...