Off sub. need help with phoneline/fax, computer.

[Imom]

We have xp, one phone line, a lexmark x75.
The Computer runs off a cable modem.
The Lexmark has a fax feat. We are trying to get working.....
Hubby hooked it up to our computer and phone line and but the voice mail picks up at four rings, so we set the fax up at 3 rings? What if someone needs to leave a message?  A friend told him about a switch we can get that tells the differents, we went to several place and they said we would not be able to find it anymore.....but we can get multirings on our phone line then set one up as the fax line.......Looked at Sbc web (our phone company) and found that feat. This is what it says on the web Multiring 1( 2.95 a month)------2 phone numbers on 1 line each with a distinctive ring.  Multiring 2 (2.00 a month)-----up to 3 phone numbers on 1 phone line each with a distinctive ring. So I call them and add the 2.00 one, he asked me how I wanted them listed, under hubby's name I said.......later on I ask him are these different phone numbers he said no?  Ok so what am I missing here how does this work?

Another question we can not get it to fax from The lexmark its self, if you pull up the lexmark all in one center and use the send a fax with your computer's modem button it scans and everything but then says line down, but if you go through control panal you can send a fax that you type up.