Hi, a bit of latency here, sorry about that.
I think the responses indicate that Mutt should use low-entropy localparts in its message-id. A couple of people strongly think so, and nobody disagrees strongly. The original issue was about the domain, which currently leaks what may be private information. For example, Message-id: <20260630abcd@arnts-imac> may reveal: * that I use a Mac, even though Macs are verboten at my workplace (I'm just making this up) * that I sent the message from my office even though I promised my wife not to work that late (I'm making up this too, honest) My suggestion was to change the domain to a constant, @message-id.mutt.org or something like that, which stops revealing the hostname but also reduces the entropy of the message-ids and thus increases the chance that two different mutt users might send a message with the same message-id. I suggested to raise the amount of entropy in the localpart to guard against that. I think it's clear that we aren't going to increase the amount of entropy in the localpart. Should we still guard against the hostname information leak, or just accept that as a non-ideal state of things? Arnt June 6, 2026 at 12:29 AM, "Steffen Nurpmeso" <[email protected] mailto:[email protected]?to=%22Steffen%20Nurpmeso%22%20%3Csteffen%40sdaoden.eu%3E > wrote: > > P.S.: > > Kevin J. McCarthy wrote in > <ahtuEwmXBaWgsbdr@qinghai>: > |On Fri, May 29, 2026 at 10:47:04AM +0200, Arnt Gulbrandsen wrote: > |>However, the sending domain isn't conveniently available at that spot > |>in the code. > | > |It could easily be made available. > ... > |I think Steffen's use of From in his reply below, or git send-email's > |usage, e.g.: <[email protected]> which uses the "@" > |in the From address as the delimiter between id-left and id-right are > |friendlier, and with the full email address give a nice uniqueness > |partition, even for "gmail" addresses. > | > |The only worry I have for Steffen's approach, is that even though '%' is > |technically allowed in id-right, the rfc recommends a domain name, and > |some spam filters may be adverse to the '%' because of that. I think > |the git approach is a bit cleaner. > ... > > But we are both "broken" if the email contains quoted-strings. > git creates > git.st"en(ey)[email protected] > for > email = s"t\"e"n(ey)[email protected] > and that from only short looking does not seem right. > > (I myself struggle for my beloved 5322/IMF parser, because > i "simply requote" local-parts which contain quotes, but i do not > think this is right either. I think local-parts are f...ed up. > And i think what they do to make it international is bad bad hack, > but that aside. (I would simply do some magic trigger thing like > they did for the IDNA i hate, or what is used for UTF-8 BOM, you > know, three full bytes of "entropy", or even more!, if that > someone has for real i cannot help it.)) > > But the thread convinced me to include further formats to only > generate the domain name of the actually used "from" address. > (For the simply MUA i maintain.) > > Ciao! > > --steffen > | > |Der Kragenbaer, The moon bear, > |der holt sich munter he cheerfully and one by one > |einen nach dem anderen runter wa.ks himself off > |(By Robert Gernhardt) >
