On Apr 7, 2014, at 7:54 AM, John R Levine <[email protected]> wrote: > I arrived to a blizzard of bounce messages this morning from my church's > discussion list, from Gmail, Hotmail/MSN/Outlook, Yahoo, and Comcast. A > little poking around with strong hints from the rejection messages revealed > that it was for a message from a member who uses a yahoo.com address, and the > problem was that someone at Yahoo decided to improve Yahoo mail's security by > publishing DMARC p=reject, leading to the exact problem I've been warning > about for a year. > > Some people claimed that list rejections are not a problem, since large mail > systems all have whitelists of mailing list servers. Unfortunately, we now > know that is not true.
It's not even slightly true. > My lists come from a dedicated IP that has been sending nothing but squeaky > clean list mail for many years. (It's listmail.iecc.com, 64.57.183.54 and > 2001:470:1f07:1126:0:62:6c61:7374, and I'm getting both v4 and v6 bounces.) > This is the same host that sends list mail from CAUCE and a bunch of other > innocuous well behaved lists. If it's not whitelisted, nothing is whitelisted. > > All church list mail has DKIM signatures from the list domain, > unitarian.ithaca.ny, and the list software, lists.iecc.com. The lists add > subject tags and message footers, which of course break the signatures, and > that's not going to change, because it's useful. The SPF is reasonable for > the list's bounce addresses. Others have seen much the same problem, at larger scales. It's not just you. > I will, of course, be urgently telling all of my Yahoo subscribers that they > need to switch to a different mail provider ASAP, but this is a dismaying > self-inflicted wound. I understand why Yahoo did this, but I think it's a very bad thing for Yahoo. Possibly also for DMARC. Cheers, Steve _______________________________________________ dmarc-discuss mailing list [email protected] http://www.dmarc.org/mailman/listinfo/dmarc-discuss NOTE: Participating in this list means you agree to the DMARC Note Well terms (http://www.dmarc.org/note_well.html)
