I tried Thunderbird for a while recently. Maybe 2-3 years, my only desktop email client, mostly because everyone talks highly about it. However, I ended up going back to the regular Apple mail, which has its flaws but I still find substantially better.
Mail is better at moving messages from folder to another, by typing names, but I absolutely can't stand the way it handles attachments, and for this alone I won't touch it with a ten foot pole
