Resolution
fact
Exchange Migrator 1.x
fact
Exchange Migrator 2.x
symptom
Error: 'Target server is unavailable.'
cause
fix
Remove or correct the LDAP referral entry, and wait for replication to occur.
Exchange Migrator 1.x
fact
Exchange Migrator 2.x
symptom
Error: 'Target server is unavailable.'
cause
An invalid LDAP referral entry existed on the target Exchange server.
For more information regarding LDAP referrals please see the following Microsoft KB article:
195104 - XADM: Configuring an LDAP Referral Server in Exchange Server 5.5
fix
Remove or correct the LDAP referral entry, and wait for replication to occur.
Additional Information
Formerly known as NETIQKB5553