On Thu, Oct 08, 2020, Harald Dunkel wrote: > Lines with a message id, and lines without. Very painful.
Maybe that's because there are sessions and transactions in SMTP. Only the latter belong to a specific message, the former can contain multiple transactions, so logging a specific message id for them is somehow wrong (unless you restrict the MTA to perform only one transaction per session). PS: some MTAs have/log ids specific to each part of the protocol: session, transaction, recipient (and even specific to the server and client side if needed).
