1/10th of 1% of what's wrong with the technology industry today
This Slack conversation about email deliverability is both dreadful and funny (because of how dreadful it is).
Generally speaking, no one knows what email deliverability is, and yet everyone who uses email deals with deliverability every day. You can send an email and it may appear like it will get delivered, but in my own estimation there is a 50% chance that the recipient will never see it, because the email never got delivered to the recipient's email inbox.
There is no widely accepted standard that is objective and independent, for an email server to decide whether an email should be delivered or not. AOL developed a pseudo-standard called SPF (Sender Policy Framework), Yahoo developed a pseudo-standard called DKIM (DomainKeys Identified Mail), and finally in 2012 a number of internet companies and organizations attempted to actually standardize policy and reporting with a framework called DMARC (Domain-based Message Authentication, Reporting & Conformance).
In practice, if you send email, you have no choice but to use all three pseudo-standards. But even if you do use all three and your configurations are correct, there is still no guarantee that the email you send will get delivered.
In the absence of an objective standard to determine whether an email is spam or not, the largest providers of "free" email accounts (Google, Yahoo, Microsoft, Comcast) simply get to decide whether an email is spam, and therefore whether an email should get delivered.
The situation is such a gigantic technical mess that i've been in numerous situations where an email sent by a Gmail account was deemed to be spam by another Gmail account (!).
This complete mess enables mafia-like behavior by email providers and companies who make it their business to "protect you by helping you decide whether an email is spam or not", most of the time charging exorbitant fees for doing so with no accountability, reporting, or transparency of any kind.
In reality the system works exactly like the mafia, with the age-old offer no one can refuse: you should pay us so that we can protect you against "threats"; and if you don't pay us, we'll blacklist you and we'll become one of the threats to the deliverability of the emails you send.
The result is that if you're a gigantic tech company that can afford to spend hundreds of millions of dollars every year to be on the right "lists", then emails coming from your domain will get delivered. But if you're a small company and can't pay the ransoms, then you may as well stop sending email because no one has any real incentive to deliver it.
The Slack conversation between three technologists is eloquent and revealing, but also extremely worrying. It's not like the US government is spending any time trying to understand why it's such a problem that "email is a cartel" and "it's not easy to get in"...