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...
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. “[M]essages...
First off, I want to thank everyone who participated in the DKIM implementation survey. This week has been pretty hectic so far, so I haven’t had a chance to actually dig down into the data from the survey, but I thought I’d post some preliminary results. The ESP survey had 45 respondents. 30% of those sent more than 15 million emails a month. Of all the respondents: 40% are signing...
DKIM has been a hot topic of discussion on some of my mailing lists today. One of the open questions is what is holding up adoption of DKIM. I have my own theories, but thought I’d throw out some questions to see how ESPs and ISPs are currently using domain based reputation. I have set up two surveys one for ESPs and one for ISPs. Responses are anonymous. I’ll collect responses for a...
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...
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...
Yesterday, on an ESPC call, Mike Adkins of AOL announced upcoming changes to the AOL reputation system. As part of these changes, AOL will be checking DKIM on the inbound. Best estimates are that this will be deployed in the first half of 2009, possibly in Q1. This is something AOL has been hinting at for most of 2008. As part of this, AOL has deployed an address where any sender can check the...
On the heels of my unsubscribe experience last week where an ESP overreacted and unsubscribed addresses that did not belong to me, I encountered another deeply broken unsubscribe process. This one is the opposite, there is no way to unsubscribe from marketing mail at all. Representatives of PayPal have only been able to suggest that if I do not want their mail, that I block PayPal in my email...
I did not have a lot of predictions for what will happen with email at the beginning of the year so I did not do a traditional beginning of the year post. Over the last 3 – 4 weeks, though, I have noticed some things that I think show where the industry is going. Authentication. In January two announcements happened that lead me to believe most legitimate mail will be DK/DKIM signed by the...
This really should be part seven of a twelve part series or some such as it deals with an aspect of DKIM that’s really important, but is way down in the details of implementation. (dkim.org is a reasonable place to start for a general overview of DKIM). There’s an apparently endless thread on the DKIM-SSP spec development mailing list at the moment about the differences between two...
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