If you are an emacs user and you are not using gnus for your email needs, you are missing out. One of the killer features in gnus is scoring. Gnus allows you to score mail on obsecne number of parameters. Sacha has done a great job of documenting her .gnus hacks in a nice article. I especially like her hack to bubble up threads with higher score up in the summary buffer. The only thing I am worried about is that soon my .emacs would be able to infer I think therefore I am.