[Mailman-Users] ARC, was non-subscribers getting through--email address in "Real Name"

[Stephen J. Turnbull]

John Levine writes:

 > As I said a few messages ago, if lists did more stringent tests on
 > incoming mail, a lot of this complexity could be avoided,

I don't understand this.  If lists got a pass, every spam would grow
RFC 2369 header fields.  No?  So ISTM the received chain needs to be
authenticated for the recipient to trust any last-hop sender, list or
not.

 > but they don't so it can't.

Origin checks are generally very useful and effective in my
experience.  But I don't see how authentication can be avoided.