A map of the creation id to an object containing the id, blobId, threadId, and size
properties for each successfully imported Email, or null if none.
The state string that will now be returned by Email/get on this account.
A map of the creation id to a SetError object for each Email that failed to be created, or
null if all successful. The possible errors are defined above.
The state string that would have been returned by Email/get on this account before making the
requested changes, or null if the server doesn’t know what the previous state string was.
The id of the account used for this call.