Forum Discussion
Hybrid - Mail Users Missing in O365
jweier_elys if you have Hybrid configured correctly, it should work as follows:
- You use Exchange on prem for all mailbox management, on-prem and online, including mailbox creation, modifying proxy addresses etc.
- You will see on-prem and online mailboxes in Exchange on-prem. The online ones will show as Office 365 mailboxes.
- You will online see online ones in Exhange online.
- The address list is synced, so users will be able to see everyone in the address book, if they are migrated or not.
- If configured correctly, it doesn't matter if you license users for Exchange online before they are migrated. This is because it knows if the users have a mailbox on prem or not through AD attribute sync. For this to work, you MUST have configured Exchange hybrid in Azure AD Connect. If you have not done that and add a license, you end up with 2 mailboxes, one on prem and one online, and a right mess.
If you migrate a mailbox and you don't see it on-prem any more, you have an issue, and I suspect you have not configured hybrid mode correctly, or enable Exchange hybid in AD connect.
CloudHal Thank you for your reply. The users I synced with AADC connect but didn't move yet eventually showed up as Mail Users. It took a handful of hours for them to show up as Mail Users after they were initially synced.
