I personally use mu4e. If you've tried it a year or so ago, it has made many improvements since then. It is terminal based, but I find I can't use thunderbird any more after switching.
So do I. offlineimap for syncing mails with my IMAP server at fastmail and mu4e for reading mails. Search is superfast, but I miss a better handling of spam mails. Thunderbird is really good at sorting out spam once you've trained the spam filter.