When reading through the Exchange Online Service Description, it clearly states that there is a built-in Deleted Mailbox Recovery Time of 30 days:
When an Exchange Online mailbox is deleted, its contents are recoverable for 30 days. A recovered mailbox contains all of the data stored in it at the time it was deleted. After 30 days, the mailbox is not recoverable. Administrators can recover a deleted mailbox using the Exchange Control Panel.
If the mailbox was originally deleted from the Exchange Control Panel and the user's account still exists in the Microsoft Online Services Portal, the administrator can recover the mailbox without assistance. If the user's account was deleted from the Microsoft Online Services Portal, then a call to Office 365 support is required in order to restore the Microsoft Online account so it can be linked to the recovered mailbox.
How does one recover a mailbox when the user has been deleted?
Time to test…
I have created a Demo User 99, and I can see this user using the Exchange Control Panel:
And when using the Exchange Management Console, connect to my online tenant,, it’s visible as well:
Using Remote PowerShell, I can clearly see that it’s a mailbox-enabled user, with one item in the mailbox:
Now, let’s delete the user Demo User 99
How can I retrieve the deleted mailbox now?
Option 1. The Shell = No
The cmdlet used in an On Premise Exchange environment, is not available Online!
Option 2. The Exchange Management Console = No
When connecting to an Exchange On Premise, you can scroll down to Recipient Configuration, and have a look in Disconnected Mailbox. But that’s not available in the EMC when connecting to an Exchange Online.
Option 3. Using the Exchange Control Panel = Yes
Open ECP, select Manage My Organization, go to Mailboxes (in Users & Groups), and select the Deleted Mailboxes…
This will show you a list of all deleted mailboxes, currently homed in de Deleted Mailbox Recovery
Select the mailbox you want to recover, and click Recover
Fill in the data needed, and click Recover
The newly created user will pop up
And the mailbox is recovered…
If you want to reconnect the mailbox to another existing user in your environment, you will need to issue a service request!
More information is available here: http://help.outlook.com/en-US/140/ms.exch.ecp.RecoverMailbox.aspx