FAX to Email/Fax detection

Hi all. We have FPBX with all the updates running on a PRI. DDI set to use system fax, with email set, a 60 second wait time. calls received on the DDI register and show the correct email target etc but the sending fax gets no tone to commence sending. has anyone found this or better still solved it?

have you reviewed the fax installation instructions

http//www.aussievoip.com/wiki/freePBX-Faxing