Cool. Quite a few of my mailing list emails haven’t got the In-Reply-To and References headers that they should have, so might be imported as new topics rather than just replies. From memory, the script uses those headers or subject headers (not both).
I think I might have asked this in the distant past, but are there any non-manual ways of adding these headers to the MBOX file and/or otherwise rearranging the emails before or after importing to Discourse?
It’s possible now to merge topics and keep chronological order so maybe that’s the answer. They’d just be missing the little Discourse arrow to signify who the message was in reply to.