>We have been having a fairly extended discussion, much of which seems hypothetical - >�I don�t like DEMARC because I am worried that ... with mailing lists�. I wonder if we >could take a moment to try it and see what happens? We've been running that experiment for at least a year. Surprise! Until a month ago, nobody noticed because there was, as far as I can tell, only one person (at Linkedin) posting from a domain with a DMARC policy. Then the during April, both Yahoo and AOL published DMARC reject policies, to try and mitigate their own problems after their respective security breaches, with the bad effects we've seen. Every time someone posts to a list from an AOL or Yahoo address, we're running that experiment whether we like it or not. R's, John