flexfax: Accounting and Billback with faxmail

[Michael Ferioli <ferioli@comnet.com.tr>]

I know this question has been asked a million times and I even
quote the bottom of the man page for faxmail:

     Because a sender's identity in an electronic mail message is
     inherently  untrustworthy,  using faxmail to build a mail to
     fax gateway is problematic.  Unless mail service is  somehow
     restricted  or  the  sender's  identity  is verified using a
     mechanism such as  RFC  1847's  multipart/signed  MIME  type
     there  is  no  reliable way to restrict access to facilities
     setup with faxmail.

Ok, so I understand the problem.  Does anyone have a real world
solution?

How about using the MTA's logs to cross reference to the xferlog?
But then again, the source IP could be spoofed.

Does anyone have any clue how an ISP can setup a mail to fax
gateway with some kind of reliable billback solution?

Thanks in advance for any help.

Mike

____________________________________________________________________
Michael Ferioli                               ferioli@comnet.net.tr
Comnet A.S.                                http://www.comnet.net.tr