CategoryDelivery Improvement

If you’re using Entrust for your BIMI VMC …

BIMI is the protocol you can use to publish an icon to display in the inbox of some large consumer webmail providers. To have it displayed at Gmail you need more than just clean DMARC and a published BIMI record, you also need to have a Verified Mark Certificate, a VMC. A VMC is a certificate, very similar in many ways to the TLS certificates used to secure webpages. It’s issued by a...

Deliveries and Opens and Clicks

I always want to say “Emails, and Opens, and Clicks… Oh My!” when I’m talking about them. We really want to understand how a mailbox provider perceives the streams of email we send them. Some of the things the provider looks at are technical and objective – is the email coming from who it claims to be coming from? Is there an attachment that contains a virus? We have...

Warmup is Communication

A still from Cargo Cult, by Bastien Dubois During the war they saw airplanes land with lots of good materials, and they want the same thing to happen now.  So they’ve arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head like headphones and bars of bamboo sticking out like...

Filter Evasion

It’s deliverability week, so everyone is talking about deliverability. But I’d like to take a moment to mention deliverability’s evil twin from the mirror universe – filter evasion. The goal of filter evasion seems at first sight very similar to that of deliverability – put the email in the inbox – but the two practices start from very different places...

Deliverability is Collaborative

Mailbox providers want happy recipients Mailbox providers want their users to be happy with the mail they receive and the service they get. That’s driven by stark business reasons: acquiring new users is costly, happy users bring in revenue – whether directly, or indirectly via advertising – and their word of mouth helps bring in more users, and hence more revenue. That’s...

It’s Deliverability Week

What is Deliverability Week? Al Iverson decided it should happen, and asked a bunch of deliverability folks to share some of their thoughts about the deliverability industry – why do we do this? where did we come from? what’s next? Monday Al’s summary of the day, Deliverability Week: Why deliverability matters to us. Deliverability Matters, and welcome to Deliverability Week...

Deliverability Week

Next week everyone will be talking Deliverability.

Inbox Jam


Spam Resource



… and more.

DNS for white label authentication with SproutDNS

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...

About My Email

Happy 2024, everyone! We’ve released a shiny new tool to let folks self-check a lot of common questions we see about email requirements. Go to and send an email to the email address it gives you. Once it receives that email it will go through it and do many of the basic checks we’d usually do to check the technical health of a client’s is a...

Yahoogle Requirements Update

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.

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