I’m sure he didn’t e-mail you out of the blue. You must’ve given his campaign your e-mail address.
I contributed to J. D. Hayworth's campaign in 2010 and have since ended up on many Republican PAC and candidate emails lists, including Ted Cruz, Scott Walker, Marco Rubio, John Bolton, Michele Bachmann, and several other prominent Republicans.
Lots of email list donating or selling going on.