Why on earth do you not allow users to disable voice mail? Don't you people realize that makes incoming faxing a problem if someone attempts to fax in while we're faxing out??
The Ma Bell mentality still rings at AT&T CallVantage. Oh well at least the customer service is still understandable on the phone and not some 7-11 Clerk in Bangladesh .. or Bangalore or wherever Vonage has it located.
I don't have AT&T CallVantage, but is there an option to extend the number of rings prior to the voice mail? If so, set it at the maximum number of rings ... the incoming fax machine would time out (error = no answer) prior to the voice mail kicking in. Test this though, as any call waiting signal might disrupt the outgoing fax... If that's the case, see if they have a prefix that would disable call waiting on any particular call... or, if CallVantage allows you to forward calls on a busy condition, get yourself one of those free j2/efax numbers, and forward the faxes to your email when the line is busy...
This is a deficiency of ATT's offering. Your only options are to disable call waiting (at which point the call goes directly to VM) or to set max rings (in which case the CW tone could interfere with the FAX in progress).
