General :: Failed To Connect To Mail Server

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

Code:
Failed to connect to mail server: Invalid argument at ./organize_bks_2 line 174

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?