Yes – you can send a fax from your computer without it being connected to a modem.
Some companies offer a free service -in exchange for advertising their services/company on your fax pages. If you don’t mind advertisments on your faxes then this option is well worth considering.
However – If you require to send/receive faxes on a more regular basis you would be best subscribing to an internet fax service where you can send and receive 100’s of pages for a rlatively small monthly subscription fee.
If you have a business and are considering moderate to heavy use – you may find a pricing tool useful. (As blelow)