Check that the Windows messaging component is installed or not.
To check this:
1.Open Add/Remove Programs from control panel.
2.Click Add/Remove Windows components. Scroll down to see that if Windows Messenger is installed.
3.If this is not installed then install this component.
Check that the windows messaging services is enabled on the client and server machines.
Steps to fix this problem:
1.From client or server machine open Services Console.
2.Double click the Messenger Service to open the properties window.
3.On the General Tab, select Automatic as the Startup Type.
4. Click OK.
5. From command prompt type 'net start messenger'.
6. The messenger service started successfully will be displayed.
7. Send the Fax now.