Fax Service Extended COM API
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/fax/faxabout_69
9l.asp

The easiest way is use an external .NET fax service, such as Interfax
(http://www.interfax.net/en/dev/).  This enables you to start faxing
with a few lines of code in your .NET development environment, and
requires no installation of servers, fax boards, or software.

Try the developer program for free.

Adam M
Interfax

Thx you guys