Do you think an Edge Server is required to take care of virus and spam? I recall that the best practice for Exchange 2003 was to install antivirus and spam on a machine separated from the mailbox store as it was prone to corruption. So we had a FE and BE configuration. Is this still the case with Exchange 2007 and Forefront security? We only have around 40-50 active mailboxes. So I'm just weighing my options, thinking whether an extra server is required.