alt Hacker NewsI'm here too.
I've used many, many different clients over the last few decades (yes, including Linux `mail`). I have to use Outlook at work, and I have to use my providers' web clients on my Windows gaming PC, but on all my other devices I use Mail.app.
I just... don't ever use all the features of the other clients, or don't like some of the behavior they have, or any of that. For a long time I would get excited about new email clients and try them out right away, but no more.
I dunno if it's just that I'm getting old, or if I just don't care as much, or both, or something else.
I use many features of Thunderbird. And it works fine with outlook, even including calendaring, with the Owl plugin. It is a paid plugin, but it makes life much better.