Question : Exchange 2007 emails going to spam folders since ISA proxy installation - how to correct?

We have Exchange 2007 set up in the building and it has been working great. Last week I set up a single NIC ISA 2006 server to do some simple web proxying so we could monitor web use. Since then however, our Exchange emails have been going into recipients spam folders. I read that this could be because our ISA server is "open" despite the fact that it is not visible publicly beyond the firewall. How can I rectify this so that our email stops going to the spam folders of recipients? I checked our public IP's reputation and it looks fine.

Answer : Exchange 2007 emails going to spam folders since ISA proxy installation - how to correct?

A single nic ISA server is not involved with email traffic - it can't be as SMTP traffic is not dealt with by proxy.