A quick marketers guide to DKIM

J.D. Falk posted a brief but comprehensive guide to the different DKIM flags: what they mean and how they may affect delivery. (The original link seems to be dead so I reproduced the blog post for reference It’s just that good. A DKIM Primer Resurrected

DKIM only answers two questions:

  • Does the message have a valid signature?
  • If it does, what domain signed it?

The signing domain, identified by the d= tag in the DKIM signature header, is the only part of the DKIM signature where the choices you make now will directly affect the continued deliverability of your messages. This is because d= is how you tell the receiving system who you are.

J.D. goes on to describe the different flags and how they may affect delivery of a particular signed message. It’s a good review of the flags and what they mean.

Irrelevant emails drive unsubscribes
Delivery delays due to congestion

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Links for 7/8/9

With all the traveling I did last month, I’m still not back to full blogging speed. I have been slowly reading through the backlog of unread posts from my RSS feeds and there was lots of good stuff published.
Three myths about DKIM by John Levine. A very good explanation taking down some of the myths of DKIM. Also on the DKIM front, RFC 5585 DKIM Service Overview was published last month. According to Cisco, DKIM adoption is climbing. More information about DKIM is available at dkim.org and our own dkimcore.org.
The always awesome guys at Mailchimp have embraced twitter as part of their platform. Not only have they  set up their own service for link shortening so that links can be tweeted, but have also incorporated twitter stats into their mail dashboard.
Al has an insightful post on delivery, spam filtering vendors and the differences (or lack thereof) between B2C and B2B marketing. As I tell my customers, there is no switch inside the filtering scheme for “I know this person, they’re OK, let the mail in.”
Terry Zink has started a series about blacklists triggered by the recent SORBS announcement.  His first post, My take on blacklists, part 2, discusses how some people go about building a blocklist from scratch.
Happy 7-8-9 everyone.

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New Delivery tools

A couple nifty new delivery tools were published over the weekend.
Mickey published Bounce P.I. where senders can paste in an error message or bounce and it will tell you what filter generated it. If the rejection is unrecognized, it will flag the message internally and it will be researched to see if the filter can be identified.
Steve has a new tool at the DKIMCore site. The key generating tool and the record checking tool have been up for a while. This weekend, though, he published a tool to check the validity the DKIM record published in DNS. Tool output shows if the record is valid, the version and the public key.

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DKIM: what it's not

An ESP twittered this past week about their new DKIM implementation going live. They were quite happy with themselves. Unfortunately, in their blog post, they mentioned 3 things that DKIM would provide for their customers, and got it wrong on all 3 points. Their confusion is something that a lot of people seem to get wrong about DKIM so I thought I would explain what was wrong.

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