List the ways an inbox can be connected

One row per provider (Gmail, Outlook, any inbox by forwarding, an address hosted here): how the connection starts (a consent screen, a forwarding rule, an address created), what the connection can do (read, or read and write), whether it imports older mail, and whether this server is set up for it. Show a connect button only when configured is true; reason names the missing variable for the operator. Requires email:read.