I am installing a Forefront TMG server to become the Edge server for a new Exchange 2010 server.
I am almost ready to bring it online but have run into a snag and need some advice if I should just change this setting or figure out what could be causing it.
My question is, on the default Exchange Mail Publish Rule SMTP Server if I leave the rule with the default setting of "Request appear to come from the original client" when inbound messages come in I look at the log and see the message "A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond" and obviously mail is not delivered to the Exchange server. Now if I change the setting to "Requests appear to come from the Forefront TMG Computer" the mail will come in and get routed to the Exchange server. Now I am basically wondering if this is something that I should not do or how can I fix this?