If you want to sign up for something and not use your own eamil, try this easy online junk mail: mailinator.com You can come up with anything and just add @mailinator.com
123456@mailinator.com
ThisIsJunkMail@mailinator.com
Quack@mailinator.com
etc...
It all works, the only caveat is that it is 100% public, anyone can view the inbox. Dont use for anything that you would care if someone got access to.

Mailinator.com

Alternately, try a temporary, but private, 60min email (unaffiliated with mailinator) at guerrillamail.com