Remote ssh tunnel in background or script?

[Kevin Kinsey]

Greetings!

I have a client who recently dropped static IP service in
favor of a "cheaper" solution, so they're now on a DHCP network
blocking port 25, etc.

In order to continue to allow them to connect to an outbound
SMTP box on the LAN, I've done this on their server:

sudo ssh -L thisbox:24:remotebox:52525 me at remotebox

I've got Sendmail listening there on 52525, and it works
fine; the local clients are told to connect to "thisbox"
port 24.  The only issue is that I have to run it from
a terminal session.  When I tried to bg the process ("cmdstring &")
it doesn't work, exactly.  I've gotten an error message
at times*, and at other times I apparently get "thisbox"
listening on port 24 but it's not an SMTP daemon that's
listening.

I have a feeling it's cause I'm in csh, which is notorious
for backgrounding issues.  <?>  At any rate, what I'd
like to do is have a script set up the connection, or
write some daemon that would monitor the connection and
fix it if it gets reset.  At any rate, if I could get this
SSH process to detach from a terminal, it'd be great.

Any suggestions?

Kevin Kinsey

* I'm sorry, but I can't reproduce the error message
this morning.  IIRC, something to the effect of
"I can't do nothing, give me a command please?"