Forum Discussion
Solved
Allow only specific domain to email a distribution group
I'd like to allow only a specific external sender domain to send email to our distribution group (DG) in M365. (The DG is actually a mail-enabled security group synced from AD.) I see that a mail-f...
I figured out a way. Using a mail flow rule where the header contains "To" of the distribution group. And have it block those messages, and an exception of the domains to allow.
VasilMichev , thanks for the clue.
I figured out a way. Using a mail flow rule where the header contains "To" of the distribution group. And have it block those messages, and an exception of the domains to allow.
VasilMichev , thanks for the clue.
Here is a screenshot of the rule 