How to Reconnect a Disconnected Archive Mailbox in Exchange 2010

When trying to connect an archive mailbox in Exchange 2010, you may receive an error

The legacy DN ‘/O=ORG/OU=FIRST ADMINISTRATIVE GROUP/CN=RECIPIENTS/CN=KIM.AKERS’ of disconnected mailbox does not match user legacy dn ‘O=ORG/OU=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=Kim.Akerts639’.

This is, in most instances, because the original user was created on in an Exchange 2003 administrative group and the new user was created on Exchange 2010 (or, presumably, 2007).

For this reason their DNs will differ. Fortunately, this is a relatively simple issue to resolve. Simply change the new user’s DN to match the old one. This should not cause you any great issue.

Changing the DN is a pretty easy task in ADSIEdit. Jump into Default Naming Context and drill down to the new user. Open their properties dialog and scroll down Attribute Editor until you find the LegacyExchangeDN property. Adjust it to match the first DN you were presented (probably containing FIRST ADMINISTRATIVE GROUP or similar). Hit OK and close ADSIEdit.

Now try to reattach the mailbox with:

Get-MailboxDatabase | Get-MailboxStatistics | Where-Object {$_.DisconnectDate –and $_.DisplayName –eq "Personal Archive – Kim Akers"} | Connect-Mailbox –user kim.akers –archive

The mailbox will now attach, and once AD replicates, will begin to map to users as appropriate.

Written on February 22, 2012