Forwarding Mail under Windows

Jacob and I work at a mid-sized university in middle Georgia, and all of the university dorms are wired. The university also has both a Computer Science program and a Business Information Systems program, so we have a lot of potential crackers live on our network before you even consider the fact that we have a T1 to the rest of the internet without a firewall ... So when I collect my mail using Eudora running on Windows, I'm not enthusiastic about having my password sent in clear text three or four times a day, or however often I press the "Check Mail" button. So I used a free Windows SSH client to secure my connection to our mail server - fortunately, we're allowed telnet and ssh access. The mail server administrator has set it up so that as soon as you log in, Pine starts up, and there's no way out to the shell (without getting very creative), but this doesn't matter: forwarding is taken care of on your local machine, so long as an SSH connection is established.

The program that I use is TeraTerm Pro, a very nice terminal emulator for Windows. It's available at http://hp.vector.co.jp/authors/VA002416/teraterm.html . You will also need the SSH extensions, available at http://www.zip.com.au/~roca/ttssh.html , which turn TeraTerm into an SSH client. Both of these are available for free. You can set port forwarding up in the "Setup" -> "SSH Forwarding" menu item, or you can do it from the command line in batch mode:

   "C:\Program Files\TTERMPRO\ttssh" mail.gcsu.edu:22 /ssh /ssh-L110:mail.gcsu.edu:110 /ssh-L25:mail.gcsu.edu:25

I then have to give a password login to the mail server. Since it's Windows, I don't have to give a root password to forward privileged ports.

The first /ssh switch tells ttssh to run in SSH mode. The next two are each just like the -L switches to ssh under Unix. I'm forwarding SMTP (port 25) and POP3 (port 110), so both sending and retrieving mail is encrypted. Sending mail this way isn't of much benefit if the mail is going out into the world, because it goes clear-text as soon as it's past the mail server, but the majority of my mail is going to recipients on the same mail server.