DeGoogle Yourself

This is what I use too and I love it. I use posteo.net domain when sharing my email address

This is extremely interesting, can I sync my Tasks.org ToDos with Posteo?

Edit: From what I understand, Tasks.org uses CalDav for ToDos which Posteo supports, but (and it sounds silly) do I have checkboxes in my calendar or something like that to know if a certain task is done or some way to see the ToDos in the same way I see them in Tasks.org? I hope they don't look like just an event in the calendar.

Have just signed up to give it a shot.

Silly question, but is there a way to create an event and invite people from an Android app? (Like outlook)

I've currently got k9, davx5. and simple calendar installed.

I created a test event in simple calendar and included my other email addresses in the attendees section. However no invite has been sent by they looks. I checked the posteo webmail page and I can see the event has been synced, but with no one invited.