Can’t migrate from Exchange 2003 directly to Exchange 2013.
You need SP3 installed for Exchange 2010 and latest roll up update for Exchange 2007 when migrating to Exchange 2013.
Can run on Server 2008 R2
Need more pre-requisites installed compared to Server 2012
No longer 5 roles – Broken down to Client access and Mailbox role.
Unified messaging included in mailbox role.
Currently no Edge server but Exchange 2010 Edge server can be used with Exchange 2013.
Only 50 databases can be mounted on a mailbox server – Exchange 2010 could mount up to 100.
Public folders are no longer replicated in multi-site environment. It will be located in one location.
Exchange 2013 is much less resource intensive with regards to IOPS on disks, so cheaper disks can be used for your Exchange server. There is approximately a 99% IOPS reduction compared to Exchange 2003.
Web App now can now be used offline.
Built-in anti-malware (Previously only anti-spam).
