How do I configure Exim as part of TPC (http://www.tpc.int))?

Suppose you want to accept faxes destined for 1(801)539-. These are addressed to the domain9.3.5.1.0.8.1.tpc.int*. Set up a transport to handle the delivery:

tpc:
  driver = pipe
  command = /usr/local/tpc/tpcmailer.pl $local_part@$domain \
    $sender_address
  pipe_as_creator

/usr/local/tpc/tpcmailer.pl is the mail processing script that can be obtained from the TPC distribution. Create a router to route mail for the TPC domain to that transport. This must be placed before your other routers:

tpc_router:
  driver = accept
  transport = tpc
  domains = *.9.3.5.1.0.8.1.tpc.int

Of course, there are other things to do as well before your system is a functioning TPC server.