Thunderbird works well for my needs. I just want to see my emails categorized in reverse chronological order. I don't expect or want any kind of filtering; I would just Sieve filters for that (running on my own server). Perhaps I am just old fashioned. Should I want AI assistance to write an email, I would fire up a local model such as GPT-OSS. Local models are more than capable for trivial tasks like this, and a smaller model on CPU only would also work.