Try this instead of the line I previously recommended:

MIME::Lite->send('smtp', 'send_by_intranet.suresoft.info', Timeout=>60
+);
[download]

(Adapted from the MIME::Lite documentation.)
Then go back to just $msg->send; . This is basically what jbrugger said in the first post, modified for the specifics of your system and without the if() statement.