I used to but not anymore. Haven't got a single piece of spam since I had the idea of making my email something like - 4xkty7dva@gmail.com. No spam program will guess that.
I do use a secondary email for forums, etc that get forwarded to my main email. If some unscrupulous webmaster sells his mailing list, I can just delete the secondary account. Easy to figure out who it was because GMail allows u to create unique addresses for each site you register on.
I too used Thunderbird but deleted it after I decided to just use the web.