When you run Microsoft Exchange Migration Wizard to move mailbox data from a Microsoft Exchange Server 5.5-based computer to a Microsoft Exchange 2000 Server-based computer, the migration may not be successful. You notice this problem when you run Microsoft Exchange Migration Wizard after you create Active Directory users by using the Active Directory Migration Tool and after you set up the Active Directory Connector (ADC). Additionally, the following events may be logged in the application event log:
Event ID: 15020
Source: msexchangemig
Description: An exchange mailbox could not be created in store LDAP://CN=Mailbox Store(SERVERNAME)
CN=First Storage Group,
CN=InformationStore,
CN=<ServerName>
CN=Servers,
CN=<AdministrativeGroupName>
CN=Administrative Groups,
CN=<OrganisationName>
CN=Microsoft Exchange,
CN=Services,
CN=Configuration,
DC=<DomainName>
DC=com,
for user LAP://CN=<UserName>,CN=Users,DC=Domain,DC=com'.
Event ID: 13002
Source: msexchangemig
Description: A mailbox could not be found in the target directory.