A small note: beside CLI MUAs there is another text-based but graphic-capable MUAs, those inside of Emacs, Notmuch in my case, and this one can really beat not

A small note: beside CLI MUAs there is another text-based but graphic-capable MUAs, those inside of Emacs, Notmuch in my case, and this one can really beat not only TB but also GMail, earlier not-so-crappy versions included. Native CardDAV integration can come via KHard or other sources, CalDAV can be integrated with org-agenda, GNUPG while not native is really quick to add, search is at another level + tags & saved searches, automation is via external tools like afew and it can be (with a not so small works, unfortunately) really efficient, for instance I auto-archive pdf attachments of my monthly bills in a proper tree, with proper filenames and a note in the org-agenda. The real problem is only that no one still do not package anything in a sole comprehensive software with a simple config. You have to make it yourself perhaps with the help of org-mode and a bit of extra scripting. A price not anyone is willing to pay but a real opportunity for ThunderBird IMO. Everything is there, needs only integration for casual users.