If we have two domains and two exchange orgs NT4 domain with Exchange 5.5 Sp3 Win2k Domain with Exchange 2000 Sp2 & we connect connect them via the ADC & the Interorg tool so they are "effectively" part of the same organisation, what would be the best tool to migrate users mailbox data? Movemailbox from Exchange 2000 Sp1 or Exmerge? And do any of these keep the single instance of a message when it is transferred? Regards Leo