@edasfr I tried Geary when I was using elementaryOS, but I found it quite buggy and some options were missing (I think it was the possibility not to display pictures in emails and disable tracking).
Evolution can be okay I think, I have never really tried it.
Maybe GNOME's new Mail app will be interesting. I like all the efforts they do to develop new apps, simple, but quite well integrated to the ecosystem.

I was just tooting about KDE Kube, but overall I still can use Thunderbird :D