Recommendations for email programs

i'm using godaddy email and it is -- well -- horrible. i was thinking of going to gmail because i really like the search and tagging functionality, and speed. (btw, i left yahoo mail -- way too slow). but, on techcrunch today, people really downed gmail. does anyone have suggestions for a useful alternative?

Thundbird used to have a lot of problems coping with voluminous email accounts. A volume of 50 emails a day quickly became unmanageable. Or at the very least it was a case a couple of years ago.