Roy,

IMO, the best way to send faxes is to use a 3rd party fax service such as www.send2fax.com or www.maxemail.com. These services allow you to email the files you want faxed to their service which in turn converts and faxes your documents to the specified fax number(s).

I believe the transmission costs are equivalent (or cheaper) than what your customer is paying for dedicated fax lines through the telephone company and is much, much, much more scalable. You can email files to these services much faster than you can fax them from your client's site.

Malcolm