flexfax: Faxmailer, should MX list be modified ? HELP!

[kpwong@psy.cuhk.edu.hk (Kit-pui Wong)]

Hello,

As the instructions, I modified sendmail.cf to accept
fax request in the format
    user@faxnumber.fax.our.domain

In order to let our BIND server to recognize 
faxnumber.fax.our.domain as a "virtual host",
I add an entry in the MX record

  *.fax           IN      A       137.189.166.200
                  IN      MX      10      harp
                  IN      MX      20      shine


Did I made the correct thing ?
Anyway, I got a "configurattion error" when sending
the fax by email. Please help! I need your advice.

   Please send a COPY of your response to my 
   email     
           kpwong@psy.cuhk.edu.hk
   'coz I didn't join the email list.

Many thanks in advance!
KiT