Some of you might have noticed a strange new addition in the EAC that showed up two months ago – under the Mail Flow tab, email address policies appeared:
As you might notice from the screenshot, the settings were actually grayed out, so we weren’t able to use the policies. While the underlying PowerShell cmdlets were also available, trying to use them yielded no result either. Few weeks later (after creating much confusion on the forums and other media), the Email address policies tab disappeared from the EAC.
Today, we finally get an answer to this little mystery – while we do get Email address policies in Office 365, they will only apply to Office 365 groups. Also, at this time, they will not be exposed via the UI and you have to use PowerShell instead. In turn, using the PowerShell cmdlets will only work when the –IncludeUnifiedGroupRecipients parameter is used, and you cannot configure Email address policies for any other recipient types. A bit disappointing 🙁
Anyway, the documentation is here should you want to play with them: https://support.office.com/en-us/article/Multi-domain-support-for-Office-365-Groups-7cf5655d-e523-4bc3-a93b-3ccebf44a01a?ui=en-US&rs=en-US&ad=US