In the previous part of this article, we covered some of the basics about what disconnected mailboxes are and showed how to ‘work’ with them in an on-premise deployment of Exchange Server 2010.
This second (short) part will focus mostly on disconnected mailboxes and archives in Office 365 (Exchange Online). As you will see, since Exchange Online is also based on Exchange Server 2010, differences are rather small and mostly due to the limitation of being a “shared platform”.
Locating disconnected/deleted mailboxes
Before, I showed you how you could find disconnected mailboxes in your environment. Working with disconnected mailboxes in Office 365 is pretty much the same. However, the example script from the previous part uses the Get-MailboxServer cmdlet which isn’t available in Exchange Online. Alternatively, you could/should use the Exchange Control Panel and navigate to the following page:
By clicking the highlighted button, a new window will appear which will provide you a list of all (soft) deleted mailboxes:
From this window, you also have the options to recover a mailbox.
Cloud-based archives (or Online Archives) are also a bit special. They exist online while the user’s mailbox can be located on-premise. If that is the case, you’ll be somehow limited in how you can treat disconnected archives.
You will only be able to reconnect the archive, by re-enabling it. For example, re-enabling the Online Archive for an on-premise user:
Enable-Mailbox <Identity> –RemoteArchive –ArchiveDomain<servicedomain>
If a disconnected archive exists, it will be reconnected. If not, a new archive will be created. Disconnected/Deleted archives will stay in Exchange Online for 30 days. After that, they are deleted and not recoverable.
Note disconnected archives will stay in Exchange Online for 30 days. After that, they are deleted and not recoverable.
Cheating to restore an (on-premise) Archive
As stated earlier, you can only restore an Archive to the user account it previously belonged to. But what if you (accidentally) deleted that account and cannot recover it from a backup? The answer is simple: you’ll have to cheat Exchange into believe that the new account you created is actually the old one. To do this, you change the legacyExchangeDN-attribute for the new user account into the value of the old user account. If you don’t know what the old value was; try reconnecting the archive: the command will fail and provide you the legacyExchangeDN it is looking for. The error will look something like this:
The legacy DN '/O=COMPANY/OU=EXCHANGE ADMINISTRATIVE GROUP (FYDIBOHF23SPDLT)/CN=RECIPIENTS/CN=<USERACCOUNT>' of disconnected mailbox does not match user legacy DN '/o=COMPANY/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=<USERACCOUNT_OLD>'.
+ CategoryInfo : NotSpecified: (Microsoft.Excha...ilboxStatistics:MailboxStatistics) [Connect-Mailbox], M
+ FullyQualifiedErrorId : 13614534,Microsoft.Exchange.Management.MapiTasks.ConnectMailbox
To work around this issue, do the following:
- Open ADSI Edit and connect to the default naming context
- Navigate to the new user’s object, and open the properties. Located the legacyExchangeDN-attribute and enter the value that was attributed to the old account. Write down the value that is currently in there so that you can change it back afterwards.
- Now, try connecting the archive to the new user account. This time, the command should succeed. (Connect-Mailbox –Identity <id> –Archive –user <(Alternative_)user>)
- Either export the archive to a PST or import the content temporarily back into the primary mailbox.
- Disable the archive.
- Change the legacyExchangeDN value back to the value you wrote down.
- Create a new archive for the user.
Changing back the the legacyExchangeDN value on the new user account avoids possible issues further down the road. Alternatively, you can run the steps above against a (service) account that you created only for this purpose. That way, you don’t have to change attributes on a user-account that is in use.
Note since you cannot alter this attribute for online users; you will not be able to run this cheat in Exchange Online. Also note that this ‘cheat’ is not supported!
Michael Van Horenbeeck