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...
DMARC makes it a year
Yesterday DMARC.org announced that in a year DMARC protects over 60 million mailboxes worldwide. DMARC, which stands for Domain-based Message Authentication, Reporting & Conformance, builds on previous email authentication advancements, SPF and DKIM, with strong protection of the author’s address (From field) and creating a feedback loop from receivers back to legitimate email senders...
New player in the DMARC space
Over on the DMARC-Discuss list, Comcast announced they had turned on DMARC validation and companies that publish DMARC records should start receiving reports from Comcast.
How long is your DKIM key?
While we were at M3AAWG, Wired published an article talking about how simple it was to crack DKIM keys. I didn’t post about it at the time because it didn’t really seem like news. DKIM keys smaller than 1024 are vulnerable and not secure and the DKIM spec does not recommend using keys smaller than 1024. When I asked the DKIM-people-who-would-know they did tell me that the news was...
Setting up DNS for sending email
Email – and email filtering – makes a lot of use of DNS, and it’s fairly easy to miss something. Here are a few checklists to help: Data you need before you start: [table] Information,for example Return path / bounce address,bounces.myesp.com Mailserver hostname,mail4.myesp.com Mailserver external address,192.0.2.4 DKIM “d=”,greatbigmarketer.com DKIM selector,oct2012...
DMARC Interoperability
Facebook hosted a DMARC interoperability event earlier this week. In terms of protocol development, interoperability events are a sign that the protocol is ready for more widespread use.
DMARC is a layer built on email authentication (SPF and DKIM) that provides brands with the ability to control use of their domains in email.
DMARC: an authentication framework
A new email industry group was announced this morning. DMARC is a group of industry participants, including large senders, large receivers and relevant intermediaries working on a framework to reduce the harm from phishing. DMARC is working on a standard to allow senders to publish sending policies and receivers to act on those policies. Currently, senders who want receivers to not deliver...