On Fri, 16 Oct 2009, hector wrote: > How does a receiver know that the client is sending list mail? Do they > need to look at some other 2822/5322 header?
In many cases, they don't. Then they have to treat dkim=except-mlist as dkim=unknown. But they lose nothing from the existence of dkim=except-mlist. But *I* can treat dkim=except-mlist as dkim=all, because my mailserver is programmed to specifically recognize the six mailing lists I am subscribed to, by their bounce addresses. In theory, a spammer could forge them, since none of them (not even spf-discuss!!) use SPF. But guessing which list to forge is an SbO that the spammers have not pierced yet.... Impersonating any list other than those 6 is futile -- it will bounce off my anti-Bcc filter. Loosely, you could say that dkim=except-mlist is equivalent to dkim=unknown when the validator is a big ISP, and equivalent to dkim=all when the validator is a vanity domain. But you don't need to be a vanity domain to *advertise* except-mlist, and us vanity domains would appreciate it if you do. ---- Michael Deutschmann <mich...@talamasca.ocis.net> _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html