> -----Original Message----- > From: ietf [mailto:ietf-bounces@xxxxxxxx] On Behalf Of Miles Fidelman > Sent: Friday, April 18, 2014 5:12 PM > Cc: ietf > Subject: Re: DMARC from the perspective of the listadmin of a bunch of > SMALL community lists > > MH Michael Hammer (5304) wrote: > > > > MH: I’m going to disagree with Murray on the fact that it’s hurting > > us, the company as the motivator, at least from my perspective. I see > > it as preventing end users from getting hurt from this particular use > > case (direct domain abuse). The further we (for some definition of we) > > can push bad actors from reality (from the users perspective), the > > less likely they are to fall for certain types of social engineering. > > I would hypothesize that increased abuse of the type Yahoo has been > > seeing may be in part due to increased difficulty on the part of > > malicious individuals in abusing brands implementing DMARC with > > p=reject. P to P mail becomes increasingly attractive and the use of > > stolen address books or user email addresses and information from > > stored messages can be used to improve the effectiveness of the social > > engineer. > > > > At least from the perspective of our lists, and spam traps - abuse of > stolen address books and such has been a much larger problem than email > from forged addresses -- at least where Yahoo is concerned, our normal > spam traps (spamassassin with lots of checks) caught (and continue to > catch) most incoming spam -- EXCEPT for the stuff that comes form > legitimate addresses. > > I.e., botnets that have access to address books and legitimate login > credentials have been the main problem we've seen. At least so far, > p=reject hasn't led to an increase in that. > The assertion has been made that the mail abusing the stolen address books was being sent from places other than yahoo.com but claiming to be from compromiseduser@xxxxxxxxx. In this scenario p=reject would have an impact in mitigating that type of abuse for mailbox providers validating DMARC (notwithstanding the damage done to mailing lists and other 3rd parties). Mike