5 つ星中 2つの評価を受けています

The difficulty is that this answers the wrong problem. The real problem is that some users send you mail in answer to a thread but it doesn't have the Message-ID in the References, so despite the Re: in the Subject line, it appears as a new thread. What is needed is a way to force such messages back into the *existing* thread that they ought to belong to, *preserving* the OP's original Message-ID. This add-on fails on both counts: it creates a new thread instead of preserving the original one, and it trashes the original Message-ID so that any more messages arriving won't have a thread to attach to.