I was working recently on a perl program on our ftp server (box is running SuSE, I belive v9.3) designed to email a warning if the mountpoint to our backup machine could not be mounted. A couple of other programs, month-end critical, took me away from that for a while. I got back to it today, only to discover that I cannot even send the messages anymore (before, I could send, but I was having trouble interpreting the results I was sending).

The program is using MIME::Lite for its mailsending function. The actual error message I am receiving is The line in question is the actual $msg->send command.

I have good reason to believe that the environment for this has changed; during the time I was working on other projects, our office phone setup was replaced and refined with an ethernet-connected setup installed by the company that provides our mailing services (and presumably network services in general, although I do not know this for a fact). I know that we were having email troubles with some of our month-end scripts after that, which required our main server's DNS values to be changed...but those errors were not the same as the one I am getting on this machine.

Is this simply going to be as easy as changing the DNS settings on our FTP box, and if not, where is the best place to start digging for more information?

It sounds like the issue you're having is that you're unable to connect to the mailserver by name. Have you tried pinging the mailserver by name from the server to see if the dns is functional? If you can't ping it by name how about ip address?