Many companies have been trying to disrupt email by making it proprietary. So far, they have failed. Email keeps being an open protocol. Hurray?
No hurray. Email is not distributed anymore. You just cannot create another first-class node of this network.
Email is now an oligopoly, a service gatekept by a few big companies which does not follow the principles of net neutrality.

We're not quite sure exactly when email was invented. Sometime around 1971. We do know exactly when spam was invented: May 3rd, 1978, when Gary Thuerk emailed 400 people an advertisement for DEC computers. It made a lot of people very angry... but it also sold a few computers, and so junk email was born.

Fast forward half a century, and the relationship between email and commerce has never been more complicated. In one sense, the utopian ideal of free, decentralised, electronic communication has come true. Email is the ultimate cross-network, cross-platform communication protocol. In another sense, it's an arms race: mail providers and ISPs implement ever more stringent checks and policies to prevent junk mail, and if that means the occasional important message gets sent to junk by mistake, then hey, no big deal - until you're sending out event tickets and discover that every company who uses Mimecast has decided your mail relay is sending junk. Marketing teams want beautiful, colourful, responsive emails, but their customers' mail clients are still using a subset of HTML 3.2 that doesn't even support CSS rules. And let's not even get started on how you design an email when half your readers will be using "dark mode" so everything ends up on a black background.

Email is too big to change, too broken to fix... and too important to ignore. So let's look at what we need to know to get it right. We'll learn about DNS, about MX and DKIM and SPF records. We'll learn about how MIME actually works (and what happens when it doesn't). We'll learn about tools like Papercut, Mailtrap, Mailjet, Foundation, and how to incorporate them into your development process. If you're lucky, you'll even learn about UTF-7, the most cursed encoding in the history of information systems. Modern email is hacks top of hacks on top of hacks... but, hey, it's also how you got your ticket to be here today, so why not come along and find out how it actually works?