E-mail is great. It is better than Facebook, Twitter, LinkedIn and all the rest for conveying messages to specific people. But there is a lot of junk e-mail that goes straight to the trash bin.
I fear a call to action e-mail would do the same. As a former lobbylist (state level) we found persoal notes did a whole lot better than e-mail, which in any cases are read by staff members, numbers tallied and the boss is told there were 1,000 e-mails and about 600 want you to do X and the rest want Y. Then the phone call comes from a major campaign contributor and the value of the 600 goes up quickly, no matter how much good information was in the e-mail.
I think social media has many uses, but because it is so easy to manipulate, I do not put much stock in what I hear was on Facebook or Twittter, etc.