the marketing name is "Mail Drop", and it is separate from iCloud mail; though it should only fire if there's a 20mb+ attachment on the email.
cloudd is used by a shit-ton of services though, so I'm not sure how to track it down without better tracing of what actually initiated the call, or the contents of the call.
cloudd is used by a shit-ton of services though, so I'm not sure how to track it down without better tracing of what actually initiated the call, or the contents of the call.
edit: tomasf nailed it - https://news.ycombinator.com/item?id=49158388