To backup your files with OneDrive, you'll need to turn on the feature in the "Backup" tab of your OneDrive settings.

If you use several devices with one Microsoft account, you can actually synchronize the content of the clipboard between all of your devices. This is useful if you want to keep your files, photos, and ...

What kind of mailbox? POP, IMAP? Obviously, and Exchange mailbox will enable this out of the box, but there must be ways to use soem kind of service to sync to web service like Google Tasks. Ah, OK.