[floathub]

The answer, as always is Emacs :-)

With mu4e (an Emacs package), you can have lightning fast searching across multiple mail accounts. And with a bit of work (https://stuff.sigvaldason.com/email.html) it will happily interoperate with Microsoft Exchange systems that require the OATH2 dance.

[CrimsonCape]

Haha, I love your reply because it brings up auth. You can't do the slightest search or action without first pinging a web server with an auth token. Yet another source of wasting milliseconds.