Socket Connection Issue

[Guest.Visitor]

I have a java app that allows me to send SMTP mail from within my RPG applications. I had originally written it and ran it on a different AS400. It worked great. I now have it loaded on another AS400 but it doesn't seem to work. It basically opens a socket connection to an ip and port address. I get a response from the mail server that it connected but then the connection seems to be closed. I have ran the app from my pc and it works fine. So I am drawing the conclusion that it isn't the application or the mail server that is causing the problem. Any ideas what might be closing the connection from the AS400 side of things? Thanks in advance for any ideas.

[JohnFox]

There could be many things: Network configuration settings on the AS/400: Can you ping the mail server from that AS400? Configuration settings on the mail server: Some mail servers can be configured to perform a reverse DNS lookup on the incomming connection and refuse the connection if the lookup fails. This could also lead to a DNS issue. Are there different versions of OS400 installed? If all of the same tools required to send e-mail are not on the 2nd AS/400, you might consider upgrading to the same release/ptf levels.