Forum Discussion
Solved
Azure AD Connect and "Exchange hybrid deployment" write-back
At a management level, one of the assumptions (correct or incorrect) when opting for Office 365 was that synchronization would be one-way (from our Active Directory to the Office 365/Azure). Unless o...
Why the need not to writeback?
If you have mailboxes both and in 365, you'll want that writeback enabled.
For example the legacyExchangeDN of a moved mailbox is written back as an X500 address on-prem to the remote mailbox .
If you dont have that, its going to cause issues for your Outlook clients with cached values and public folders.
It really depends on what you're planning on making use of in Office 365. Some things will have more affect than others by not having exchange Online. Not setting hybrid isn't required initially unless you are going to host mailboxes in both locations at the same time. Nothing writes back via Azure AD unless you have premium P1 and configure it too. The only thing that writes back in a hybrid setup is the migration jobs, they will talk back and tell your migration endpoint to basically inform your on-prem server that the mailbox was moved and mark it as in the cloud, but that's not AzureAD doing that, that's Exchange Services.