Hello: I wonder if lei should inject its own "received"-like header on writing to a maildir/imap target -- to indicate where the copy of the email came from. I don't think it should use the actual Received: header, as this may cause some weird SPF/DMARC issues, but perhaps something like:
X-Lei-Received: from https://lore.kernel.org/all/; Fri, 19 Nov 2021
14:32:44 -0500
Just a random thought.
-K
