Why can't a basic computer system be used to fax a letter?

A basic computer can be used to send a fax. You can send a fax for free with many free sites like FaxZero with limitations like maybe just being able to send a maximum of 2 pages in the fax and you need an internet connection. For those without internet connection and you want to use your telephone line like a traditional fax, you can purchase a program called HotFax 5.0 I think it might be discontinued but you can still buy it at Amazon. I had it years ago and it worked great for sending and receiving unlimited faxes for one price around $55. I don't have a landline any more so I don't use it now. Currently, I have been using FaxZero for sending all of faxes for the past 2 years and I use k7 to receive my faxes. Best thing about it, it's free! If you are doing high volume and do not have a landline telephone then I suggest signing up for efax