A user must have an Exchange Online license in order to access a shared mailbox. Shared mailboxes don’t require a separate license. However, if you want to enable In-Place Archive for a shared mailbox, you must assign an Exchange Online Plan 1 or Exchange Online Plan 2 license to the mailbox. If you want to enable In-Place Hold for a shared mailbox, you must assign an Exchange Online Plan 2 license to the mailbox. After a license is assigned to a shared mailbox, the mailbox size will increase to that of the licensed plan.
So for the purpose of this blog, I am going to focus on three issues:
- How large can a shared mailbox (no license) be?
- Can you put shared mailboxes into litigation hold or in-place hold?
- If you needed >10GB mailboxes or in place hold, how would you assign a license?
Based on the service description, you need a license for both litigation hold or in-place hold.
Here's the GUI versus powershell of my in place hold. You can see that in shell it shows there are no sourcemailboxes but the GUI shows I have an in place hold. Confusing and very misleading.
And my test eDiscovery with in place hold seems to be capturing data:
And the preview shows my data!
What about litigation hold? Well, that allows me to set it:
But can we trust it? Is it really holding data? The answer is yes. Here's a trimmed screenshot of a prior test (not the same as the in-place hold) that captured data. Even better, this mailbox was deleted, so this also proves that it is in litigation hold since the mailbox is no longer enabled, we know we are not searching an active mailbox.
If you needed >10GB mailboxes or in place hold, how would you assign a license?
According to the Service Description, if you need in place hold or larger than 10GB shared mailboxes, you need to assign an Exchange Online Plan 1 or Plan 2 license to the mailbox.
- This is no longer a shared mailbox, but is a user mailbox that is shared, it now has a username and password (and the password assigned is not very complex if a cloud only account (@tenant.onmicrosoft.com)
- This is now a cloud only account, if you run DirSync or had a security requirement that all accounts be sourced in AD, this would not be within that policy, or subject to any policies your authentication solution might enforce. If you had a Hybrid environment, you could convert and move the shared user mailbox to on premise, or just create your shared mailboxes on premise
- Licensing does not appear to be required to have in-place or litigation hold enabled
UPDATE 10/8/2014: Another nod to Nino - In this article, Microsoft addresses Exchange Online licensing required and explicitly mentions Litigation Hold as WELL as in place hold require an Exchange plan 2 license!
Manage inactive mailboxes in Exchange Online
- Quota, litigation and in-place hold all function as expected on shared mailboxes without a license, however this could change and be enforced at any given time, so obviously recommend using licensing if the functionality is needed.
- Litigation and in-place hold are completely enabled for shared mailboxes, regardless of the licensing section of the Service Description
- Licensing a shared mailbox can be performed by converting them to a user mailbox or by assigning a license to the shared mailbox MSOLUser as documented above