I already asked this in the TMG forums and didnt really get the answers there, so hoping I get better luck here, so slightly rephrased:
Environment:
- Two Windows 2008 R2, Exchange 2010 SP3 servers, currently holding all mailboxes
- Two Windows 2012 R2, Exchange 2013 SP1 servers, setup in progress
- Two Windows 2008 R2, TMG 2010, V7.0.9193.540 publishing both Exchange 2010 servers.
Scenario:
I need to allow incoming and outgoing emails through TMG to both Exchange 2010 and 2013 as it will take me weeks, if not months before all mailboxes are in 2013.
Question:
1. How do I need to configure TMG to allow both Exchange 2010 and 2013 simultaneously?
2. Do I just redirect all SMTP to Exchange 2010 mailboxes to Exchanges 2013 in TMG and 2013 just pass on the traffic to 2010 if it doesn't have the mailbox?
Hoping to hear from someone whos actually had 2010/2013 in coexistence with TMG doing the publishing and firewalling for Exchange. Thanks.