User-agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6b) Gecko/20031204 Thunderbird/0.4RC1
Have you looked at something like Shorewall? It's a firewall system
designed to be added to a GNU/Linux distro, although I have never used
it (only heard good things) so can't vouch for the install.
Downloaded and installed Shorewall and WebMin.
It looks like it working, but, when I activate the Shorewall firewall
it's completely locked down! Looks like I'll have to play about with it
to get it working properly!!
Cheers
Simon
___________________________________________________________________