Re: smtp - can it be ssh tunneled?

[Kevin Falcone <kevinfal@seas.upenn.edu>]

>>>>> "HP" == Harry Putnam <reader@newsguy.com> writes:

  HP> I don't really understand ssh port forwarding but is it possible
  HP> to forward the port that my outgoing mail uses to my ISPs smtp
  HP> port and dump my mail in that way?

If you use smtpmail.el to send mail, then

ssh -L 2525:mail.server:25 shell.server

will point port 2525 on the localhost to 25 on the mailserver,
bouncing it through the shell.server so that it appears that the smtp
conversation is coming from the shell.server.

  HP> Or maybe the opposite way round.  Ssh to the ISP machine then
  HP> forward port 25 to my home machine. And aim sendmail at
  HP> `localhost 25' or something similar.

I do this:

ssh -C -q -L 2525:sierra.seas.upenn.edu:25  blue.seas.upenn.edu

then I twiddled sendmail.cf (not recommended) for the Msmtp Mesmtp
Msmtp8 and Mrelay lines to say localhost 2525 instead of localhost 25

So, gnus invokes sendmail on bowline.jibsheet.com, whose sendmail
relays through sierra.seas.upenn.edu using the ssh port forward from
2525 to 25.

If you want more details, feel free to reply offlist.

-kevin

-- 
"Never go in against a sicilian when death is on the line" 
    -- Vizzini in "The Princess Bride"