I've been using E-Smith for about 4 years now for my home gateway, website, FTP, email, etc...
I talked a friend of mine into using it as well and learning as I did, but we've come across a snag. I get my internet access from a friend's company and got a static business IP. He has cable with a residential IP. As quite a bit of the email from his IP would be blocked since it comes from a residential IP he wants to use his ISPs mail servers for his personal email. E-Smith seems to be blocking it, however. He can receive his email just fine, but he cannot send anything to anyone but himself. Wierdest thing I've seen in a long time.
Does anyone have any ideas what might be causing this?