I really enjoyed being able to have a "unified inbox" across multiple accounts.
It was also very smooth, and I didn't have to wait around for it doing who knows what, but this hasn't been an issue with KMail when I used it regularly some 12 years ago (without Exchange, though). Only Outlook ever felt noticeably slow.
Some other creature comforts were great, like integration with quick look (tap space on an attachment, and you can see it in a popup).
I could also have a unified calendar with my personal (Gmail) and work (Exchange online) accounts.
I only had to tell it "this is my exchange account, and this is my gmail account, now do your thing" – and it did, complete with OAuth2 and all.
I haven't tried KMail recently, but last I've seen (a few years ago) it didn't support Exchange online.
Thunderbid had some Exchange support, but it was a bit wonky (around 2019). I don't think the calendar was actually working. Maybe things have improved, I seem to remember there was a major upgrade recently.
Evolution, IIRC, had some kind of support via EWS, but I never "clicked" with it so never tried it seriously. Installing a gazillion gnome packages didn't help its case, either (I don't use gnome otherwise). According to the Arch Wiki [0] it should support mail + calendar through MS's Exchange ActiveSync (which is proprietary, but I don't have an issue with that if it works).
It was also very smooth, and I didn't have to wait around for it doing who knows what, but this hasn't been an issue with KMail when I used it regularly some 12 years ago (without Exchange, though). Only Outlook ever felt noticeably slow.
Some other creature comforts were great, like integration with quick look (tap space on an attachment, and you can see it in a popup).
I could also have a unified calendar with my personal (Gmail) and work (Exchange online) accounts.
I only had to tell it "this is my exchange account, and this is my gmail account, now do your thing" – and it did, complete with OAuth2 and all.
I haven't tried KMail recently, but last I've seen (a few years ago) it didn't support Exchange online.
Thunderbid had some Exchange support, but it was a bit wonky (around 2019). I don't think the calendar was actually working. Maybe things have improved, I seem to remember there was a major upgrade recently.
Evolution, IIRC, had some kind of support via EWS, but I never "clicked" with it so never tried it seriously. Installing a gazillion gnome packages didn't help its case, either (I don't use gnome otherwise). According to the Arch Wiki [0] it should support mail + calendar through MS's Exchange ActiveSync (which is proprietary, but I don't have an issue with that if it works).
[0] https://wiki.archlinux.org/title/GNOME/Evolution#Microsoft_E...