http://blogs.technet.com/mfugatt/archive/2008/06/13/significant-update-to-the-mailbox-server-role-storage-requirements-calculator-v-14-7.aspxhttp://msexchangeteam.com/archive/2008/06/12/449007.aspxen-GBCommunityServer 2.1 SP1 (Build: 61025.2)