You can determine labels, it's just more work. I wrote a script a while back that used IMAP to just generate a list of message-ids and the labels associated wit

You can determine labels, it's just more work. I wrote a script a while back that used IMAP to just generate a list of message-ids and the labels associated with each one. I iterated over all messages in all folders to build the associations. It might be possible to query for a single message-id in all folders, to get a list of labels to, but you would need to know the message-id ahead of time.