Exchange 2003 how ro remove a ophaned mailbox

I need to remove a small number of mailboxes from Exchange 2003, they were linked to a Windows 2003 child domain controller that does not exist anymore.

If I try to run exchange tasks on the mailbox it is unable to see the removed server, error "A referral was returned from the server ID No: 8007202b"

The reason I need to remove the mailboxes is because I need to re-create the logins on the primary Windows 2003 DC, but it knows the e-mail box exists and will not let me create a duplicate e-mail address.

I have been looking at ADSIEDIT to remove the homeMDBBL attribute, to see if this will help me but I get the error "The attribute cannot be modified because it is owned by the system.