Andrew, thanks for your feedback! Very informative. I have mentioned the information to our list. Probably we have to rollback and not use SES.
On Fri, May 5, 2023 at 3:53 AM Andrew Hodgson <andrew@hodgson.io> wrote:
Sam Darwin wrote:
We recently switch the mail gateway from mailgun to Amazon SES. There's a new problem that the mailman 2 archives are not able to group threads together the way they were before. Moreover, end users have their own mail clients that display the list messages, and they are complaining about issues in their local mail clients. It seems to be related to the mail header fields >Message-ID: , References: , and In-Reply-To: .
Amazon SES rewrites the Message-ID.
Yep and for this reason I don't use it. The problem is worse in Mailman3 because it has a much more superior archive display which gets ruined when people reply to messages with different Message-Id headers and the threading can't be observed. I also had to use the anonymous mode with my list as Amazon didn't like me using random addresses in the From: header.
I'm still looking for a tolerant mail gateway to use with Mailman.
Andrew.