This number is the fax number from a company called SaveOnFaxes. It is an email fax company. They translate your digital email into fax and fax the information to the fax numbers you provide. (I believe they are being bought or sold to Fax2Mail because I get links to both companies in my when I send a fax with the service). I just signed up for service yesterday, and when I tested the service out by sending a fax to myself I got the 732.542.3012 number in the 'subject' field when the fax was delivered to my inbox.
My belief is that people are just signing up for the service and spamming you. This is really the only way I can believe that such a great volume of spams could be generated and not have been shut down. Spammers sign up for the service needing only an email address with no identity verification, they sit at their computers and send out thousands of emails knowing that when you receive their fax the only thing you'll have to contact them with is a fake email address they made when they opened the account. IF you follow the trail you'll just be returned to the saveonfaxes number, which is who you should call: 866-924-6096.