Mass faxing is a great way to bypass the cluttered e-mail inboxes of your clients and get a physical piece of paper in their hands. A fax machine is not required or even usable for mass faxing. You need a computer and an internet connection.
What You Need
Use a simple online calculator to figure out which service is the cheapest for your needs. Go over your needs and use the first link (Faxprices.com) in the resources section.
Pricing varies widely, depending on what company you are dealing with. Most companies will charge a set-up fee, but almost every company offers a free trial that you can use to test out their service.
Pay attention to how the pricing scheme works. Try to establish a price per fax number for the different companies or packages you are comparing. After you do this, look at the extra features that come with each package to make your final decision.
What to Look For
Besides price per page, pay attention to other features such a storage space and toll free fax number. Also look at the rates for faxing to other countries. One site, Fax1.com, charges 12 cents per page to the US, but charges 1.99 per page to Equatorial Guinea. Consider using email instead of faxing if possible for your international clients because faxing internationally can be very expensive. In general, however, you can expect rates to most first world countries to be roughly double (20 to 30 cents per page) the rate to the US.
If you are planning on sending only one or two short faxes each day, you can do this for free. Use faxzero.com to send a free fax to anyone in the U.S. or Canada for free. Faxzero also offers a paid service but it is not price efficient for sending out dozens of faxes per day.