Good Discussion on this topic at Linked in is HERE
Elan Sudnow Wrote: “..It’s based on business and technical drivers. Each solution needs to fit a need. Does the current solution in the environment provide adequate capabilities to meet those needs? If the answer is no, then the Exchange Edge may benefit your organization….”
Edge Role – HMC & Exchange 2010 SP1 Hosting:
I see that in the new EX2010 SP1 Hosting that the Edge Role is no longer supported.
What’s not available in Exchange 2010 SP1 Hosting Mode…..
http://technet.microsoft.com/en-us/library/ff923272.aspx
Implement.com SI Wrote….
“…HMC 4.5 replaced the Edge Server Role with Internet Facing HUB Servers. This was primarily due to the Accepted Domain and Email Address replication delays associated with getting up to date values out to the Edge Servers and also the Edge Cache refresh which combined meant it could be up to 8 hours for Edge servers to start accepting email for a new organization or email address. Most Service Providers found this to be unacceptable and so never deployed the Edge Role…”
Interesting blog post here on Mail Transport…
http://blogs.technet.com/b/provtest/archive/2010/07/27/exchange-server-2010-sp1-beta-hosting-deployment-part-7-transport-segregation.aspx
The Future is...Cloudy 