Migrating shared mailboxes between hybrid environments on same Office 365 tenant

[Emond Lo]

Hi there,

We have the following setup:

One Office 365 tenant shared by multiple on-premises Active Directories, all using Dirsync to sync accounts up to Office 365. All are hybrid setup and no on-premises Exchange server. Say we have AD "A" and AD "B".

We have some shared mailboxes, initially defined as user accounts, in AD "A", which were sync'd up to Office 365 and converted to shared mailboxes. Management is done at AD "A".

We want to move these mailboxes from AD "A" to AD "B". Anyone know of any tools I can use to do that please? I don't want to break the mailboxes in Office 365.

Currently, I know I can create the shared mailbox in AD "B". Then manually migrate the mailbox content from the old to the new one and then delete the object in AD "A". As there are quite a few I am hoping to find other ways to do it.

Thanks,

Edmond.

[#2]

A quicker way, although not really supported one, would be to filter the shared mailbox out of the scope of the "A" DirSync. This will remove it in O365, but you can immediately recover it from the recycle bin, which will leave it as "disconnector". Meaning, you can now remove it's immutableID and match it against any other On-Prem object (including the ones from other ADs).