DMARC is the newest of the authentication protocols. It compares the domain in the From: address to the domains authenticated by SPF and DKIM. If either SPF or DKIM pass and they are in the same organizational domain as the domain in the From: address then the email is authenticated with DMARC. I wrote A Brief DMARC primer back in 2014 – when Yahoo deployed p=reject late on a Friday and...
The gentleman with the excellent hat is Иван IV Васильевич, The Great Sovereign, Tsar and Grand Prince of all Russia, Vladimir, Moscow, Novgorod, Tsar of Kazan, Tsar of Astrakhan, Sovereign of Pskov, Grand Prince of Smolensk, Tver, Yugorsk, Perm, Vyatka, Bolgar and others, Sovereign and Grand Prince of Novgorod of the Lower Land, Chernigov, Ryazan, Polotsk, Rostov, Yaroslavl, Beloozero, Livonia...
A common complaint about the advice or answers any deliverability person gives is that the generic answer to questions is: It Depends. This is frustrating for a lot of folks because they think they’re asking a simple question and so, clearly, there should be one, simple, clear answer. The problem is that there is almost never one answer in deliverability and details do matter. Let’s...
I wrote last year about using “stunt” nameservers for customer subdomain authentication – i.e. dynamically generating all the authentication records needed in DNS for each customer as needed. For example, if you’re an ESP that has customers who can’t or won’t use their own domains and you still need to give them unique subdomains you can generate CNAME records...
On January 9th at 6pm GMT, 1pm EST and 10am PST I’ll be speaking with Nout Boctor-Smith of Nine Lives Digital about the new Yahoo and Google technical requirements. In this webinar you’ll: Learn more about what these new email sender guidelines entail and how they differ from the status quo Understand why you’re being asked to do things that were previously handled by your...
Since I wrote about it last month the requirements for bulk senders to Yahoo and Google have changed a little.
The big change is that bulk senders need to authenticate with both SPF and DKIM, rather than SPF or DKIM. Only one of those has to align with the 822 From: header.
EDIT: Now with a production-ready implementation I talk about more here. On Tuesday I wrote about using DNS wildcards to implement customer-specific subdomains for email authentication. As I said then, that approach isn’t perfect. You’d much prefer to have per-customer domain authentication, where each customer has their own DKIM d= and ideally their own SPF records, rather than...
If you’re an ESP with small customers you may have looked at the recent Google / Yahoo requirements around DMARC-style alignment for authentication and panicked a bit. Don’t impersonate Gmail From: headers. Gmail will begin using a DMARC quarantine enforcement policy, and impersonating Gmail From: headers might impact your email delivery.…For direct mail, the domain in the...
UPDATE: You need to authenticate with both DKIM and SPF. Google are circulating a new set of requirements for bulk senders on their blog. So are Yahoo. It’s almost like postmasters talk to each other or something. If you dig through the links in the Gmail blog post you can find this summary of what they’ll be requiring from bulk senders by February: Set up SPF or DKIM email...
Another day, another ESP telling a client to publish a SPF include for the wrong domain. It shouldn’t annoy me, really. It’s mostly harmless and it’s just an extra DNS look up for most companies. Heck, we followed Mailchimp’s advice and added their include to our bare root domain and it’s not really a huge deal for companies with only a couple SaaS providers. Still...
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