Yesterday I mentioned that there were reports of a compromise at AOL. While the details are hazy, what has been reported is that people’s address books were stolen. The reports suggest lots of people are getting mail from AOL addresses that they have received mail from in the past, but that mail is coming from non AOL servers. In an apparent effort to address this, AOL announced today they...
ReturnPath on DMARC+Yahoo
Over at ReturnPath Christine has an excellent non-technical summary of the DMARC+Yahoo situation, along with some solid recommendations for what actions you might take to avoid the operational problems it can cause.
Yahoo Statement on DMARC policy
Yesterday Yahoo posted a statement about their new p=reject policy. Based on this statement I don’t expect Yahoo to be rolling back the policy any time soon. It seems it was incredibly effective at stopping spoofed Yahoo mail. On Friday afternoon last week, Yahoo made a simple change to its DMARC policy from “report” to “reject”. In other words, we requested that all other mail services...
Dealing with DMARC for Mail intermediaries
I’ve been getting some mail and calls from folks looking for help on resolving the issue of DMARC bouncing. Some of these calls are from ESPs, but others are from SAAS providers who have users that have signed up with yahoo.com addresses and are now dealing with mail from those users bouncing, even when mail is going back too those users. None of the solutions are really great, but here are...
Yahoo DMARC articles worth reading
There are a bunch of them and they’re all worth reading. I have more to say about DMARC, both in terms of advice for senders and list managers affected by this, and in terms of the broader implications of this policy decision. But those articles are going to take me a little longer to write. How widespread is the problem? Andrew Barrett publishes numbers, pulled from his employer, related...
Fixing discussion lists to work with new Yahoo policy
Al has some really good advice on how to fix discussion lists to work with the new Yahoo policy. One thing I would add is the suggestion to actually check dmarc records before assuming policy. This will not only mean you’re not having to rewrite things that don’t need to be rewritten, but it will also mean you won’t be caught flat footed if (when?) other free mail providers...
Example bounces due to Yahoo p=reject
There are a number of different bounces that people are reporting due to Yahoo publishing a DMARC record of p=reject. I decided to put some of those bounces here so confused users could find out what they needed to do. Comcast smtp;550 5.2.0 meQj1n01053u42A0HeQj3v Message rejected due to DMARC. Please see Google smtp;550 5.7.1 Unauthenticated email from yahoo.com is not accepted due to...
A brief DMARC primer
DMARC stands for Domain-based Message Authentication, Reporting and Conformance. What DMARC does is allow domain owners to publish policy statements in DNS telling receiver domains what to do with messages that do not authenticate. In addition, DMARC introduces the concept of “domain alignment.” What this means is that the authentication has to be from the same domain (or a sub...
CNN warns about Target copy-cat phishes
Target did indeed do a blast to customers to offer one year of free credit monitoring. The problem is scammers are also on the prowl and are sending out similar emails. Target even says it has identified and stopped at least 12 scams preying on consumers via email, Facebook and other outlets.CNN: Did you get an email from Target? I’m not surprised in the least that phishers are copy-catting...
DMARC: Please Be Careful!
(Cross posted from Spam Resource.) Every couple of days, somebody new pops up on the DMARC-Discuss mailing list to ask some question or share an observation. It’s great to see people interested and joining the conversation. Clearly, DMARC interest and adoption are growing. What’s really frustrating, though, is that for about a quarter of the new subscribers, their first mailing list...