Sharepoint 3.0 shared fax on SBS 2008

I have WSS 3.0 running on an SBS 2008 box with an internal modem. The modem appears to run fine as it will send and is receiving faxes.
It appears to me from the appearance of the Sharepoint fax center that it will allow users to send faxes but I cannot figure out how. I am not that knowledgeable and so I don't know if it has to do with setting up a shared fax printer or what exactly. I configured the fax printer in sbs console.
Faxes are already appearing in the "incoming faxes" folder but sent faxes (using Windows fax and scan) do not appear in the "Sent faxes" folder.
No error messages
Can someone advise whether WSS has the capability and how to implement it?
Thanks.