> Does it automatically filter my email into tabs for primary, promotions, social, and updates?
This is where email MUAs[0] shine. Mail user agents such as Thunderbird[1], KMail[2], Apple Mail[3], and nmh[4] (for hard-core Unix command-line aficionados) support filtering and automatic categorization to varying degrees.
All while being mail service agnostic.
0 - https://en.wikipedia.org/wiki/Email_client
1 - https://en.wikipedia.org/wiki/Mozilla_Thunderbird
2 - https://apps.kde.org/kmail2/
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?
Ahem, https://neomutt.org/
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.