Are you ready for DMARC?

secure_email_blogThe next step in email authentication is DMARC. I wrote a Brief DMARC primer a few years ago to help clear up some of the questions about DMARC and alignment. But I didn’t talk much about where DMARC was going. Part of the reason was I didn’t know where things were going and too much was unclear to even speculate.
We’re almost 2 years down the line from the security issues that prompted Yahoo to turn on p=reject in their DMARC record. This broke a lot of common uses of email. A lot of the damage created by this has been mitigated and efforts to fix it continue. There’s even an IETF draft looking at ways to transfer authentication through mailing lists and third parties.
For 2016, DMARC alignment is going to be a major factor in deliverability for bulk email, even in the absence of a published DMARC record.

What’s DMARC alignment?

DMARC alignment is where either the Return Path (5321.From, Envelope From, Bounce String) or the DKIM d= value is in the same domain space as the visible from address (5322.From, sender).

Why do you think so?

I’m already seeing some delivery issues for certain domains that are unaligned, particularly at ISPs like AOL and Yahoo.

What do I do?

If you’re an ESP customer, ask your ESP about using a custom bounce string / return path so your domain aligns. You just need to add a MX record for that domain that points to the ESPs bounce handler.
If you’re an ESP customer and can’t add a MX, ask them about signing your mail with a custom DKIM key that is at your domain. You will need to do a little DNS work – either publishing your public key yourself or publishing a DNS record that points to their public key server.
If you’re an ESP, and you can’t sign with custom keys or handle custom 5321.From addresses, you need to look at your development path and figure out how fast you can do either.

I’m not publishing DMARC, so this doesn’t affect me.

ISPs are already evaluating DMARC alignment on all incoming mail.
dmarc=pass (aol.com: the domain example.com reports that SPF aligns in relaxed mode, DKIM is unaligned.) header.from=test.example.com;
It’s a short step to use that as part of their delivery decisions, particularly when there is no alignment.

My unaligned mail is delivering just fine.

I’m sure it is. I also don’t think that’s a given for the future. I think it’s wise to be looking to have as much of your mail as possible aligned sooner rather than later. 

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A brief history of TXT Records

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When the Domain Name System was designed thirty years ago the concept behind it was pretty simple. It’s mostly just a distributed database that lets you map hostname / query-type pairs to values.
If you want to know the IP address of cnn.com, you look up {cnn.com, A} and get back a couple of IP addresses. If you want to know where to send mail for aol.com users, you look up {aol.com, MX} and you get a set of four hostname / preference pairs back. If you want to know the hostname for the IP address 206.190.36.45 you look up {45.36.190.206.in-addr.arpa, PTR} and get a hostname back.
There’s a well-defined meaning to each of those query types  – A is for IP addresses, MX is for mailservers, PTR is for hostnames – and that was always the intent for how DNS should work.
When DNS was first standardized, though, there was one query type that didn’t really have any semantic meaning:

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Email predictions for 2015

Welcome to a whole new year. It seems the changing of the year brings out people predicting what they think will happen in the coming year. It’s something I’ve indulged in a couple times over my years of blogging, but email is a generally stable technology and it’s kind of boring to predict a new interface or a minor tweak to filters. Of course, many bloggers will go way out on a limb and predict the death of email, but I think that’s been way over done.
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Even major technical advancements, like authentication protocols and the rise of IPv6, are not usually sudden. They’re discussed and refined through the IETF process. While some of these changes may seem “all of a sudden” to some end users, they’re usually the result of years of work from dedicated volunteers. The internet really doesn’t do flag days.
One major change in 2014, that had significant implications for email as a whole, was a free mail provider abruptly publishing a DMARC p=reject policy. This caused a lot of issues for some small business senders and for many individual users. Mailing list maintainers are still dealing with some of the fallout, and there are ongoing discussions about how best to mitigate the problems DMARC causes non-commercial email.
Still, DMARC as a protocol has been in development for a few years. A number of large brands and commercial organizations were publishing p=reject policies. The big mail providers were implementing DMARC checking, and rejection, on their inbound mail. In fact, this rollout is one of the reasons that the publishing of p=reject was a problem. With the flip of a switch, mail that was once deliverable became undeliverable.
Looking back through any of the 2014 predictions, I don’t think anyone predicted that two major mailbox providers would implement p=reject policies, causing widespread delivery failures across the Internet. I certainly wouldn’t have predicted it, all of my discussions with people about DMARC centered around business using DMARC to protect their brand. No one mentioned ISPs using it to force their customers away from 3rd party services and discussion lists.
I think the only constant in the world of email is change, and most of the time that change isn’t that massive or sudden, 2014 and the DMARC upheaval notwithstanding.
But, still, I have some thoughts on what might happen in the coming year. Mostly more of the same as we’ve seen over the last few years. But there are a couple areas I think we’ll see some progress made.

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Looking forward

The nice folks over at Sparkpost asked me and other email experts for some thoughts on what we think the most important issues in email will be in 2016.
I do think security is going to be a major, major change in delivery. From what I’ve seen there’s been a shift in the mindset of a lot of people. Previously a lot of folks in the email space were very accommodating to old systems and unauthenticated mail and were not quite ready to cut off senders that didn’t meet modern standards.
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There were a lot of people who didn’t want to take any action that would break email. There are still a lot of people who think that breaking email is a bad thing and changes should be backwards compatible.
Then people started realizing not every change had to be backwards compatible.
 
There are a few reasons I think this attitude shift happened.

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