Hello Colleagues, The NANOG mailing list had a discussion several months back regarding changes that Yahoo made to their DMARC settings. Over the past day, the NANOG mailing list has received a number of posts from yahoo.com mail users. This triggered bounce action on nearly 300 NANOG mailing list subscriptions as the receiving mail systems were complying with the DMARC settings that Yahoo has set. All subscriptions that had been disabled have been re-enabled at this time. To correct this moving forward, selective rewriting of the from header has been recommended, but requires an upgrade to the Mailman software. While we would like to have no impact to our subscribers, the selective rewrite and upgrade are not immediately available. An expeditious implementation of the upgrade is being worked on. As a temporary measure, the NANOG mailing list will be holding posts that come from yahoo.com users. We are not wishing to restrict posting, however posts from yahoo.com accounts are causing operational issues with the mailing list. Once a final timeline for the upgrade procedure and selective rewrite are available, we will let you know. Best Regards, Andrew Koch NANOG Communications Committee