Because of the nature of this problem, could you send any advise or help by e-mail to mtdew321@yahoo.com. We are running Exchange Server 5.5 on a Win NT 4.0 system. Due to poor installation of the software the first time, we had to “wipe the slate clean”as they say and reinstalled the Exchange server. We were able to send and receive outside e-mail for a little while after that, but now we can’t (Internal mail is alright so messages are being delivered inside our LAN). I have checked the settings and they look like they should work but I am a novice on the Exchanger Server. I need to know what settings need to be in place to receive and send e-mail, so I can double check them. I have pinged our ISP and it replies fine. Although they seem fine, could the problem be in the radio that is receiving the signal from the ISP or the firewall that has been setup (Obviously we are getting on the Internet). Any suggestions would be appreciated. Thanks