As simple as the title sounds I'm having huge trouble getting that working.

Thunderbird only fetches new mail while it's open.

Who the heck knows how to get evolution/geary to play nice with business gmail/protonmail.

Does anyone have a simple way of solving this problem?

edit. Also, somewhat related, is there a good looking, simple e-mail client? Thunderbird looks busy. Geary kinda looks okay but I cant get it to work at all.