We are upgrading ISA 2006 to TMG 2010. We are currently using ISA 2006 as our SMTP relay from internal to external mail and vice versa. I am unsure if TMG 2010 will still support this without having an Exchange Edge server to relay and cannot find documentation to support this. We cannot install the Edge role on the existing TMG server because Exchange 2007 roles are not currently supported on Windows Server 2008 R2 and doesn't appear they will be until the second half of this year (http://msexchangeteam.com/archive/2009/11/30/453327.aspx). Does anyone have documentation to show that mail relay will work on TMG 2010 without the Edge server role installed so I can still build the TMG server on Windows 2008 R2 without having a separate Edge server on Windows 2008 standard? All we really want to do is mirror what we're currently doing on ISA 2006.
Yes, you can still create non-Web publishing rules and access rules for SMTP, just like you could in ISA Server.
I must say, the lack of support for Exchange 2007 on WinServ2008 R2 is a real problem. For instance, TMG 2010 appliances from manufacturers, including Celestix and nAppliance, are all built on R2. This means that Exchange 2007 organisations wishing to take advantage of TMG's integrated E-mail features have a big problem. You could try installing an Exchange 2010 Edge Transport server instead, but you'd lose functionality (recipient filtering etc).
Otherwise, it's a case of waiting for SP3 for Exchange 2007 I'm afraid.
Thanks for the reply. We have decided to go forward with installing the Edge Transport Role on a separate server in our DMZ. Now all that remains is configuring the TMG server to relay to this server. Any documentation on doing this?