My question is quite simple. I would like to have the word INTERNAL added to emails that: are sent only from within the organization; and are received only by the organization; and are not sent to anyone outside of the organization; and are not copied to anyone outside the organization. This is very basic but it appears that there is no negative condition on Mail Flow rules. I appreciate your help. Fabiano

Changing Subject Line for Internal Emails

Fabiano 1

My question is quite simple.

I would like to have the word INTERNAL added to emails that:

This is very basic but it appears that there is no negative condition on Mail Flow rules.

I appreciate your help.

Fabiano

Joyce Shen - MSFT 16,641 Reputation points

2021-11-04T03:37:32.603+00:00

Hi @Fabiano

I have test your requirement in my environment and I'm afraid this cannot be achieved. Mailflow rule will take effect when the condition is achieved.
So the message received by external users are normal however internal users will still have the subject prepended with "Internal"

Are you using On-prem Exchange server or O365? If you are using O365, I would suggest you openning a service request to O365 backend to feedback this situation and your expectations. Thanks for your understanding!
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Fabiano 1 Reputation point

2021-11-04T09:10:01.257+00:00

Thank you, Joyce. I use O365 and do as you suggested.