Send As permissions for mailboxes in Exchange Online where the user was still within the on-premises Exchange environment has always been a point of discussion. Officially it wasn’t (/isn’t….) supported by Microsoft. There were some known workarounds which did the trick most of the times, like re-applying the permissions, but these were officially not supported.
It looks like this is about to change…..or not…..
I recently noticed a change on the official documentation, where Send As was officially stated as supported:
However, it seems that the documentation was published too soon because it has been reverted as of January 17th.
So does this mean that we’re getting close for an official supported scenario for Send As permissions??
Michel van Vliet - IT Blog 
Leave a Reply