I tried the built-in Vivaldi email. It looks good. But we use Firefox. You know, you create habits and then they are hard to change. And when you have to change the habits of 5 people of different ages, it is even harder. Yes, Thunderbird has everything you could possibly need. But it is a bit like Microsoft. There are too many things that you don't need.
Anyway, the other day I changed Fedora to Solus on my laptop and installed Geary. The others continue with Fedora and Mailspring, I don't need the features of this email client, I feel a little bad that I am with Solus and they are with Fedora, but I will get over it. 🙂