Hi Remco, So I'm looking at 9da4e6e11e7037668d0ca7e8f5d6773d26e379ac (I noticed this in mutt 2.0.2 on FreeBSD)
This is a bad change for public mail archives which use https://$SOMETHING_SOMETHING/$MSGID for robustness across different public mail archives and hosts. Encoding YYYYmmddHHMMSS into the Message-ID doesn't hurt users privacy in cases where mutt is generating the Date: header. Having the date information in the Message-ID (and thus archive URL) is an important reference for quickly identifying the message date without having to open the URL itself. This saves readers time and bandwidth. Yes, I realize all that can be faked, but legitimate Message-IDs and URLs cited in commit messages are unlikely to be. The git.git and Linux kernel development communities are heavily reliant on Message-IDs for identifying messages so they're not tied to any centralized service (which can go down, like gmane). Having a little bit of extra information for humans to identify with is far better than completely random characters. I agree adding some randomness after YYYYmmddHHMMSS is necessary, and PID was a bad choice originally; but YYYYmmddHHMMSS is a good prefix. I actually think having good, memorable Message-IDs can help mutt attract some users away from MUAs/services that generate less memorable Message-IDs :) Thanks for reading.
