In a recent announcement in Message Center, Microsoft is letting customers know about upcoming changes to how Office 365 IP address and URL details are published.
You should not disable the Windows Firewall on Exchange servers.
Microsoft has published detailed information about Exchange Server 2013 network port requirements.
This tutorial demonstrates how to configure ISA Server 2006 to allow Exchange 2010 mailbox access by remote email clients.
Tom Shinder of ISAServer.org takes an amusing shot at the myth in some circles that a "hardware" firewall or "firewall…