hmm, if I can still read english, you have 2 computers one is set up as a dedicated firewall only and its your suse / mandrake computer we are talking about.
I can't help you.
If you are interested, the firewall guarddog has an option to make a rule lets call it 143 and then you allow rule 143 access to the net. www.rpmfind.net
should have a RH with luck. Otherwise the author site is