Here is a small list of free internet faxing. The list is found herehttp://fax.1888usa.com/
There are more services just type into Google: faxing for free
Most of the free services are advertising supported, so it appears on the cover page. So the benefit might be, it will look like it's coming from some company.
I prefer the browser based faxing, as opposed to email. If you use an email address, most likely you'll eventually get unwanted emails.
Prepare your message to Senator. Save it as text file, copy and paste it into the appropriate box, and send your message.
If you use MS Word, Acrobat (to create a pdf), these files contain personal info embedded into the file header. You really don't want to give this info to some free service. This is why I suggest creating a text file using notepad (clean with no personal info).
The benefit of sending a fax is:
1. if the receiver receives faxes via email, the fax is an image. Unless the receiver has sophisticated OCR software, the fax has to be either printed or viewed on-screen. So anti-spam software is generally useless.
2. if the receiver uses a real fax machine, the the fax is printed.
I picked this tip up from the Alex Jones/Sam Labrier podcast.
Maybe a thread can be started with Senator's fax numbers.
and try this site.http://www.congressfax.com/