Mail only sends locally

[MattSharp]

I work on a network at my school. We have our own network within the schoo's network. We have a webserver and a fileserver. The fileserver is also what we use as our mail server. This server sends mail to everyone, everywhere with no problems. Our webserver, however, sends mail only locally within the schools network. When it attempts to send mail outside of the schools network it times out while communicating with the destination's server. The problem is that our web server is where Mailman is, and that is what I need working right now.

So I first ask if anyone has any ideas of what the problem might be? The school's people took their firewall down briefly and allowed us to try to send mail but that still didn't work eliminating that possibility. I think there might still be a DNS problem of sorts that is causing things to not work.

I am currently looking for a temporary solution to by myself time to work on the problem. I know I could install Mailman on the file/mail server, but that can be complicated sometimes. I was wondering if there is a way to re-route mail to be sent from the fileserver instead of the webserver? Of course if you have any incite on the root of the problem thats good too.

[kopfarzt]

First: mail problems always can have many different reasons.

What you should check first is whether you can make connections from your web-server to some mailhost on port 25, e.g.:

[MattSharp]

I tried three different mail servers on three different hosts and all of them connected no problem. Not slow or anything. We have a firewall on our own server, not the school's one, that I could try taking down but I didn't want to risk MSBlaster getting in our network, since I would say only 50% of the computers are patched.

[devon]

Does your mail server have a PTR entry in DNS? E.g.