As I wrote on G+, I never liked Thunderbird. There is no email client today that I like: they’re all based on very old concepts developed at the time when people had to deal with few messages per week. The only innovation I’ve seen in email came from Google’s Gmail, with the convenient conversation view and with the great integration of chat and addressbook with Circles. Gmail is not the email client I use: I never bought into that sort of convenience. I always wished that somebody would develop a new, modern, email client for my desktop.
With Thunderbird at its sunset and GNOME Evolution its only viable substitute, I’m starting to despair. I have some hopes on Geary, Yorba Foundation’s new email client.