Am 04.05.2023 um 01:49 schrieb Gavin Lambert via Boost:

On 4/05/2023 03:55, Andrey Semashev wrote:

...

The fact that the initial message is not part of the thread now is a relatively recent issue. This is the mailman archive from a year ago:

https://lists.boost.org/Archives/boost/2022/04/index.php

Threading is fine there. In fact, threading was working correctly as recently as in February 2023:

https://lists.boost.org/Archives/boost/2023/02/index.php

and has been broken in March:

https://lists.boost.org/Archives/boost/2023/03/index.php

If the system works (and worked) the way you describe, mailman was able to associate the initial message with the thread before and now it isn't. I suspect, this may have something to do with the headers that are added by SES to the messages it sends to the subscribers.

Threading only sometimes works in the gmane view as well.  Usually it's not the mailing list itself at fault, but due to the mail client used by the person posting -- or sometimes that they're replying to a digest rather than the original mail, so the context headers are lost (even if they edit it to look like it was a reply to a single post).

I have noticed an apparent increase recently in the number of posts that appear "flat" or semi-flat (still showing as a reply, but to a grandparent post rather than the real parent post) -- but other recent threads still do appear normally nested, so I don't think it's a systemic issue.

I get the posts on the ML delivered as individual emails to my client (Thunderbird) and I can see the routing. Threading was fine until the end of February (through mailgun.net), and is broken since the beginning of March (through amazonses.com). The transition can be seen in the thread "Has testing on msvc been dropped?) in Tom Kent's posts. Dani -- PGP/GPG: 2CCB 3ECB 0954 5CD3 B0DB 6AA0 BA03 56A1 2C4638C5