I have moved several users from one OU to another. We do this each year for
students at the beginning of the each. Now, several students (not all) are
unable to login to their mail. They receive an LDAP failure and the PO
shows 2AB LDAP error 32 (username)

I have checked the GW diagnostic information against the edir user object it
does show the correct distinguished name. Sometimes doing a gwsync works and
sometimes disassociate and reassociate edir object but frequently that
doesn't work. Deleting the GW mailbox and recreating a new mailbox does
work. Things were fine until I moved the users to a new OU