We've put together a overview of DMARC: https://youtu.be/kGk-Af_92Bk This video is part of a larger video series on all things DMARC. The transcript follows: (more…)
dmarcian7 December 2015
DMARC introduces the concept of "Identifier Alignment" to the world of email. The concept is needed as SPF and DKIM are stand-alone technologies capable of associating a domain with a piece of email. When a receiver uses SPF, the receiver looks at the domain found in the RFC5321.MailFrom to figure out where to look for…
dmarcian12 October 2015
Yahoo is placing ymail.com and rocketmail.com into p=reject on November 2nd. This information is being provided to give people and companies time to prepare, as the #1 piece of feedback from when Yahoo moved yahoo.com to a p=reject was that Yahoo didn't let the Internet know about the move in advance. Hopefully, this announcement will…
dmarcian12 October 2015
People sometimes write in and ask "what is the impact of a broken SPF record"? The net effect of a broken SPF record is that receivers can't reliably use SPF to determine the legitimacy of the domain's email. *Some* receivers might ignore the broken parts of an SPF record and keep checking, but out of…
dmarcian10 October 2015
If PTR mechanisms are detected, the current diagnostic output is: Warning: PTR mechanisms SHOULD NOT be used and cannot be resolved using this diagnostic tool. What does the PTR mechanism mean? When an email receiver gets a piece of email and the PTR mechanism is in the sender's SPF record, the receiver will look at…
dmarcian9 October 2015
If you publish an SPF record and use the a mechanism, but your domain doesn't actually have an A record in place, then you'll see this warning. Here's a sample SPF record that contains the a mechanism (the a is in bold): v=spf1 a include:_spf.google.com ~all The A DNS record is how you use the…
dmarcian8 October 2015
Users sometimes ask What does "No DMARC reports received yet which confirm DKIM signing" mean? dmarcian uses DMARC-XML data to detect the presence of DKIM signatures. There is no straight-forward way to query the internet for the presence of DKIM signatures, and so dmarcian relies on the contents of DMARC-XML reports to provide information on…
dmarcian7 October 2015
