Just starting a forum won't get you members or traffic, if you did email people firstly you'd need a mailing list and secondly bulk emailing will probably be interpreted as spam and get you blacklisted.
Unfortunately getting a forum off the ground is long hard work, make sure you get your url's submitted to search engines, answer questions or write in similar forums answering with good content and have a link to your forum in your signature, write in blogs...etc
It really is hard work until you get going