I've now purchased the mailbox and pop2pipe modules and implemented them. There was a Perl configuration error that my ISP fixed for me. Also, the documentation says you should use "perl mailbox.cgi -s" in pop2pipe only for Windows systems but I had to as well and I'm pretty certain I'm on a Linux server.
In order to run pop2pipe regularly I used Website-Watcher (
www.aignes.com), a very useful tool that automatically monitors changes to web pages. In this case it just runs the pop2pipe script to poll the POP3 inbox every hour.
One thing that really impresses me is that once a ticket has been assigned to an operator, all the correspondence can take place using only e-mail - neither the user nor the operator ever need to login to TTX. But, since all e-mails pass through TTX, you get a very good log of the conversation taking place!