Anyone notice this: You search for an important clients email, and Apple mail, brings up one conversation from one folder, but not an original email that is even more important from another. It's like it vanished from earth. Very frustrating, I don't know how to explain it better, as it's maddening when it happens.

Posts in numerous forums complain about searching in Apple Mail. Most often it is attributed to Spotlight not yet finished with its indexing. If this is truly driving you crazy, look into Foxtrot Personal Search. It has been favorably reviewed for its search capabilities, especially where e-mail is concerned.