I did it anyway some time ago and I'm really happy with it. I'm using my own email addresses for absolutely anything by now.

Thats called a calendar and is preinstalled on almost any device.

.box since it's recognized as valid TLD by many devices. Never use .local it's reserved for multicast DNS.

Wtf why YT Premium?!

I pay for a small VPS thats running my mail server and other extremely important services.