I wish Tbird would become usable for me, but every time I try, it falls very very short in polish, in performance, and in capability.
Mac's native Mail program works super super well for me and my enormous corpus of mail, search is nearly instant, and it talks to IMAP and Exchange with ease. It's also reasonably easy to look at. I get some folks don't care for it, and I absolutely concede that the old saw about "the worst one, except for all the others" still applies, but for me, Tbird is just one of "all the others."
Mac's native Mail program works super super well for me and my enormous corpus of mail, search is nearly instant, and it talks to IMAP and Exchange with ease. It's also reasonably easy to look at. I get some folks don't care for it, and I absolutely concede that the old saw about "the worst one, except for all the others" still applies, but for me, Tbird is just one of "all the others."