I have less than 2000 mailboxes on Exchange Server 2007. My users are a mixture of Outlook 2007/20010 clients on PCs (30 %) and Citrix XenApp (70%).
I have 1 mailbox server, 1 CAS server for ActiveSync access, 1 UM server, and 2 HT servers for message routing. All servers are virtualized on VMware in a single site. OWA is currently disabled for all users. I currently use public folders.
I'm planning to migrate to Exchange Server 2013 rather quickly in order to begin utilizing my DR site for switchovers/failovers. My intent is to use a single DAG to replicate 20 databases between three mailbox servers. Two of these mailbox servers will be in my main site, each containing 10 primary and 10 secondary copies, effectively spreading my users between the two servers. The third mailbox server will be in my DR site, containing secondary copies of the 20 databases. I will use hardware load balancers in each site for connections to multiple CAS servers in each location.
I will be implementing a new MDM platform as part of this migration, so I plan on using a new namespace for ActiveSync access.
My initial testing leads me to believe my existing users on Exchange Server 2007 will continue to function as they do now (communicating via RPC with the mailbox server) until their mailboxes are migrated to an Exchange Server 2013 mailbox server. Is it at that point that they will start communicating via the Exchange Server 2013 CAS servers? Should Outlook profile changes should be automatic once a mailbox has been migrated?
Should I move the public folders before or after completing the mailbox moves?
Should I be concerned with creating the legacy namespace since I am not currently publishing OWA and I will be creating a new namespace for ActiveSync access (user switches to new MDM platform at migration time)?
All outbound e-mail is currently routed through a smart host via a send connector. Should I plan to perform this function with a send connector in Exchange Server 2013 immediately or should I wait to move this until after I get a portion of my users migrated?
Thank you for any insight/advice anyone wishes to provide.