Vivaldi is a webbrowser many people never heard of. Its is a chrome based alternative to Googles chrome browser. It comes with built in privacy protections, ad-blocker, calendar, rss-reader and now an e-mail client thats out of of beta to version 1.0. Its available for Windows, Android, Macos, and Linux distrubutions. You can also use all chrome addons if u wish and it offers a free email option. You can have multiple browser profiles options wich is encrypted and synced via servers in Iceland.
The company behind it is based in norway
zdnet reviewed it and was impressed.
Vivaldi Mail is one of the best web browser-based mail clients I’ve used in a long time…
Link to review below
https://www.zdnet.com/article/vivaldi-now-offers-a-built-in-mail-client-thats-pretty-fabulous/