In the US at least, Fax sometimes has trouble co-existing with DSL.  Furthermore, Fax is extremely unreliable when using VOIP (IP phones, Vonage, etc..).

I became very frustrated with having a fax machine in my office, and switched over to MyFax.com.  For $10/month you e-mail your file to MyFax.com and they will automatically send the fax on your behalf.  There are lots of other services that do the same thing.  $10/mo might sound expensive, but in reality, it probably saves money compared to buying toner for your fax machine and dealing with all of the DSL/Fax compatibility hassles.  (You still need a good scanner attached to your PC obviously).

This is not really a suggestion, just an exploration. Would it be hugely difficult to implement fax messages?

As far as I understand it, with client computer and dsl line alone, fax is impossible, because of dsl frequency. Those who have dsl modem and 56k modem can often send fax. Some line me only have a dsl line, with phone provided computerized by the ISP.

My ISP makes me go online to my client space, there I give a recipient phone number and select a pdf file on my computer to send, and the pdf becomes a fax at the other end.

Fax is out of fashion, except for legally binding documents. So it's quaint and serious at the same time. It's compulsory in lawyers' offices for instance.

There exists a Mercury Fax daemon somewhere. But for all our clients we suggest/install all-in-one printers, and they work perfectly side by side with dsl carrier lines. The frequency problems only arise if there is a miswiring of the phone lines, making the dsl frequency filter unuseful.

[quote user="Peter Strömblad"] But for all our clients we suggest/install all-in-one printers[/quote]

You mean hardware all-in-one printers, right?

Yep, their printer drivers let's anyone fax through them. What you maybe could do is create a filter within Mercury to re-route messages to a connected net use lpt port and send that out.