* Austin Witmer via Postfix-users: > Will DMARC be broken if I only add the following headers to mailing > list messages? [...]
Adding *new* headers can't break existing DKIM signatures, because these headers cannot have been signed before. New in this case means header names (not values) which have not been present before. > X-Mailinglist: > List-Id: > List-Unsubscribe: > List-Unsubscribe-Post: If, for example, a user sends any of his messages with X-Mailinglist: yes please! and also includes this header in his DKIM signature, you adding another header with the same name or replacing the value can break the existing signature. Headers with the 'X-' prefix are not standardised, so anybody can use them willy-nilly. Will they do that? Possibly. Remember that there are many weird people out there. ;-) -Ralph _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
