Comment 112 for bug 44335

If you can't recompile, you can use Stunnel. It binds to a port on your computer and forwards traffic with encryption (like ssh, but you don't need a shell account on the remote host). This is how Conky does secure email checks. Read the Conky FAQ at http://conky.sourceforge.net/faq.html (Q #10) to get it working. The Stunnel configuration will work just as well for mail-notification as it will for Conky.

You may even end up replacing mail-notification with Conky, like I did.