I've tried Thunderbird, Kmail, and Apple's client, and maybe I just have too many emails, but these apps completely crumble under my inbox. I don't see any "shine" with these third-party clients. Mimestream, my favorite email client on macOS, "just works" because it uses the Gmail API. It seems like Fastmail made JMAP, but this doesn't seem widely supported.

Are there mail clients that actually support things like priority inbox and categorization that don't simply crumble for large inboxes?

> Are there mail clients that actually support things like priority inbox and categorization that don't simply crumble for large inboxes?

Of the exemplars listed, nmh is by far the most flexible and capable of handling large inboxes. The reason why is that it is a set of command-line executables which can be scripted with whatever language you prefer. So prioritization and/or categorization is a matter of how one wants each to be defined.

I used IMAP via fetchmail[0] with nmh to allow multiple MUAs (on different machines and/or OSs) access/management to the same email accounts with great success. IIRC, for nmh I used lynx to render HTML messages and xview to display image attachments. Other attachments were processed separately but had similar workflows.

0 - https://www.fetchmail.info/fetchmail-man.html

Thunderbird does not seem to have auto-categorization from what I see, just filtering. Neither does KMail. Unless you’re referring to some addons? For apple mail you have to add it on each client. And a lot of comments are about how to disable it because it categorizes wrong.

It’s not that making rules isn’t possible, it’s that it’s done automatically, out of the box, correctly by Gmail.

Ahem, https://neomutt.org/

Good call!

I have not used mutt myself, but have heard great things about it and it is definitely worthy of consideration.

Frankly I've tried quite a few clients and haven't found one I can settle for. I used Mailspring for a while because it was close to being a gmail experience, but that went some kind of bad way I don't remember and I don't think is developed anymore.

I want a client that is simple but flexible by default, extensible, themeable would be nice, and for the love of god has key shortcuts for everything THAT CAN BE CHANGED. LOOKING AT YOU, THUNDERBIRD.

Thunderbird is almost usable for me, but the UI is just absolutely abysmal. The kicker is not being able to change key shortcuts, making Thunderbird unusable for me.