Thunderbird's slowness and other quirks got me to switch from it to the Windows mail app when I'm on Windows... suffice to say I don't recommend it. It looks n

Thunderbird's slowness and other quirks got me to switch from it to the Windows mail app when I'm on Windows... suffice to say I don't recommend it. It looks nice and all, but isn't necessarily all that much faster, doesn't always render HTML email all that well, and has pieces of basic functionality mysteriously missing (i.e., to this day it doesn't understand what the Reply-To header is for). Chalk it up as another in a long line of Thunderbird alternatives that just don't measure up. I'd love to have something else I like (especially now in the twilight of XUL) but it's just a tough space.