I'm trying to split a thread / conversation in Apple Mail 5.2 (the one on Lion). What I've done so far is trying to remove the references and reply-to from the mail files, but for some reason this didn't work - it only worked when I copied the .mbox file somewhere else, changed the message id of the message I'm trying to split off the thread (as well as the subject), imported the .mbox file and deleted the original message.
So now my question is - how does that make any sense whatsoever? Isn't it normal to edit the References header and remove the message id of the mail this is a reply to? And how does Mail know by the reply's message id that it's part of the conversation? Also, do you think it's safe to mess around with message ids or will that come back to bite me later?