Hi, First some background: DKIM allows a mail server to sign mails similar to GPG, except that the public key is distributed via DNS. DMARC allows a domain to define a policy (do nothing, quarantine or reject) for mails that do not possess a valid DKIM signature (modified content, spam mail without a sig, ..). DKIM signatures sign both, the body and the header of the mail. The header fields that are signed differ between setups, but generally it's at least From, To and Subject. Currently, most/all of our mailing lists prepend the listname to the subject, thus invalidating any DKIM signature. Some lists also add a footer to the body of the message (arch-events, possibly more). I propose that we configure our lists not to alter messages in any way so that existing DKIM signatures remain valid. This would mean that the list name will no longer be in the subject so everyone who currently uses that to filter list traffic would have to switch to using the List-ID header. This is also a much more reliable way to filter list traffic since sometimes mails have multiple tags in the subject if they are sent to multiple lists. Also private messages may still contain the subject tag even if they were never sent via the list. I don't see any benefit in having the listname in the subject since mails are generally filtered into dedicated mailboxes per list anyway. Changing the subject just means that when browsing that mailbox all subjects start with the same useless text. I know multiple lists that have already switched to keeping mails as-is. Among them are the bugtraq and cgit lists as well as some official and third-party dovecot and postfix related lists. If this proposal is accepted by us, I will send it out to all our lists with a 2 week lead time before I start changing anything so that people have a chance to update their filters if necessary. Opinions? PS: I'd prefer to keep discussion on arch-devops@lists.archlinux.org. I'm just posting this to arch-dev-public so all devs/TUs are aware of it. Florian