Exchange Easily Convert Linked Mailboxes to User Mailboxes

Sometimes when migrating to Exchange 2010, mailboxes will move over as Linked Mailboxes, even though they're not associated with an external account.

The supported way to convert them, according to an MS TechNet article is to disable the mailbox and then connect it to an existing account...that's a lot of unnecessary work!

There are two easier ways to go about converting Linked Mailboxes:

The "unsupported" way using ADSIEdit
Disclaimer: this works perfectly, but you can break things with ADSIEdit so only change the value listed:

Fire up ADSIEdit.

Find the account that is listed as a Linked Mailbox.

Change the msExchRecipientTypeDetails value from 2 to 1 then force an AD replication.

Wait until replication is complete and check that the Linked Mailbox is now a User Mailbox in the EMC.

Bulk convert Linked Mailboxes with PowerShell:

Start the Exchange Management Shell and run:

Get-Mailbox -RecipientTypeDetails LinkedMailbox | Set-User -LinkedMasterAccount $null

Now all wrongly classified Linked Mailboxes will be User Mailboxes. Neither of these methods will have any adverse effects on the accounts or mailflow...everything will still work as designed.