Why does Mail app contact iCloud when sending a non-iCloud email?

Fun activity: install glasswire on windows for a day or 2, set it to prompt you before any connection is allowed, and watch as about 500 different windows components attempt connections with Microsoft as a result of any and every action. And how many onedrive exes randomly fire off throughout the day despite having never once used it. And how onedrive changes its version number every day when it realizes it can’t connect.

I assume for the same reason the OS pings Cupertino when you run a binary - surveillance, masquerading as protection.

Probably Handoff and cross-device application state syncing.

Everyone wearing their tinfoil hat while using Gmail and drive for everything