flexfax: Sending a fax with HylaFax+Class1 to a shared fax line

["Jonathan I. Kamens" <jik@kamens.brookline.ma.us>]

I'm running HylaFax v4.0pl1 with a Class 1 fax modem (SupraExpress
56e).

I'm trying to send a fax to a telephone line that is shared between
voice and fax use.  The owner of the line told me, "Just hit send
right after dialing; don't wait for the fax machine to answer."  But I
don't know how to tell hylafax and/or my modem to assume that the
other fax machine is going to answer and start negotiating right away,
so I am unable to send the fax.  I've tried to just send it normally,
and it doesn't work.

I assume that my modem is sending a CNG tone, and I know that the
stuff at the other end of the line should be smart enough to detect
the CNG tone and switch to fax mode.  But since it's not, is there any
way I can convince the software or hardware at my end of the line to
jump right into sending the fax immediately after it dials?

(BTW, I've checked the FAQ and the documentation for my modem, and I
also did a DejaNews search, but I couldn't find an answer to this
question.)

Thanks,

  jik