[HECnet] Fwd: [H390-MVS] Yahoo DMARC Implementation Breaks Most Mailing Lists

Hello! See below. That was just sent to the H390-MVS list. John if you don't see that here say so. ----- Gregg C Levine gregg.drwho8 at gmail.com "This signature fought the Time Wars, time and again." ---------- Forwarded message ---------- From: <afg0510 at videotron.ca> Date: Thu, Apr 10, 2014 at 5:32 PM Subject: [H390-MVS] Yahoo DMARC Implementation Breaks Most Mailing Lists To: H390-MVS at yahoogroups.com FYO - on http://tech.slashdot.org/story/14/04/09/2047205/yahoo-dmarc-implementation-… pdclarry writes: "On April 8, Yahoo implemented a new DMARC policy that essentially bars any Yahoo user from accessing mailing lists hosted anywhere except on Yahoo and Google. While Yahoo is the initiator, it also affects Comcast, AT&T, Rogers, SBCGlobal, and several other ISPs. Internet Engineering Council expert John R. Levine, a specialist in email infrastructure and spam filtering, said, 'Yahoo breaks every mailing list in the world including the IETF's' on the Internet Engineering Task Force (IETF) list. DMARC (Domain-based Message Authentication, Reporting & Conformance) is a two-year-old proposed standard previously discussed on Slashdot that is intended to curb email abuse, including spoofing and phishing. Unfortunately, as implemented by Yahoo, it claims most mailing list users as collateral damage. Messages posted to mailing lists (including listserv, mailman, majordomo, etc) by Yahoo subscribers are blocked when the list forwards them to other Yahoo (and other participating ISPs) subscribers. List members not using Yahoo or its partners are not affected and will receive posts from Yahoo users. Posts from non-Yahoo users are delivered to Yahoo members. So essentially those suffering the most are Yahoo's (and Comcast's, and AT&T's, etc) own customers. The Hacker News has details about why DMARC has this effect on mailing lists. Their best proposed solution is to ban Yahoo email users from mailing lists and encourage them to switch to other ISPs. Unfortunately, it isn't just Yahoo, although they are getting the most attention."