Archive Users Mailbox To Shared Mailbox

Occasional Contributor



Can anyone see a reason why we can't convert old users mailboxes to shared mailboxes instead of archiving them to a PST and deleting the account?


The theory behind it is shared mailbox licences are free and the email data can still be accessed.




5 Replies

Hi Kevin,


Normally that should work just fine. I've done this for lots of mailboxes already. Do you receive any error message when you try to convert a normal mailbox to a shared mailbox?


Best regards,

Ruud Gijsbers

best response confirmed by Kevin Carne (Occasional Contributor)

Hi Kevin,


It should work without any problem, and shared mailboxes does not need licenses.


But you can manage inactive mailboxes also using retention policies. Please read here


Here the main article

Thanks for your help guys.


No not had problems just wanted to know if we can do it in theory.


Litigation hold or retention policies will work great but not for our smaller clients who are on business licences.



Be careful here. If you simply convert the old mailbox to a shared mailbox, you need to also take care of the email addresses for the mailbox, its membership of DLs, groups, teams, etc., and the fact that it still appears in the GAL. A more complete answer is to convert, change the SMTP address of the object so that it doesn't receive new email, and hide it from the GAL so that people don't see it in the directory. Unless of course you want the shared mailbox to keep on receiving email and have its membership maintained...
I know this is an old post and I don't know how much of this has changed, but we had an issue where we converted to a shared mailbox but we lost all the archived emails for the mailbox that we converted. Maybe we have to change the retention policy on the shared mailbox? How large can the shared mailbox be? The converted user had an Exchange Online P2 so they had a large archive.