The majority of professionals on the Internet receive recruiter emails on a consistent basis, to the point many of them are junked without being read. In many ways. The name of the game here is not quantity, it's the quality of the people you contact, the targeting of your audience, the reputation as a good shop to work with . The Internet allows for people around the world to communicate - take advantage of that aspect. Disclose all the information you can.
Candidates talk, candidates email, candidates have a pretty good idea of their worth already.
Most likely, especially in the technical fields, they know what their peers are getting. Of course not. The more you demonstrate your understanding of this medium, the more impressed your potential candidates will be. Barbara Ling has been an active participant on the Internet since 1988. She is the author of The Internet Recruiting Edge, a comprehensive guide for recruiters using the web.