Currently on Protonmail and Protoncalendar.
- [Guide on Proton and Mutt](https://brian-thompson.medium.com/setting-up-the-mutt-mail-client-with-protonmail-49c042486b3)

But interested in checking out these projects for inspiration only,
because not everything has to be google calendar/icalendar, oof:
https://wiki.nikiv.dev/macos/apps/fantastical#links
