[woodruffw]

> when people have very accessible choices of email providers and what they tie to it.

I think this point might have been true 15 or 20 years ago, but I suspect that it no longer is on either front:

* E-mail is increasingly non-federated and subject to Google's dictates w/r/t delivery guarantees, origin identification, &c. These aren't bad things; e-mail was a mess before Google started taking it seriously! But it does result in a sort of natural dominance: smaller providers have to play by Google's rules to ensure delivery; large institutions are less likely to debug delivery issues to smaller providers. In other words, I have to be willing to accept a certain amount of second-class treatment.

* It's been my experience that my ability to not tie things to my e-mail has diminished over the years. More recent government systems and financial accounts require a valid e-mail; e-mail + password is now the default setting for creating an account on most services. Even when my e-mail is strictly optional for a service, it frequently operates as a safety net (recovery codes, poor man's 2FA, &c). Put another way: my inbox is treated as the high-availability, high-reliability delivery mechanism.

[jolmg]

Regarding your first point, is that from experience? Have you known of a case where a large institution sends a legitimate email to a small provider, the small provider rejects it, and the large institution does nothing about it?

If you're paying for your email provider, I would think opening up a ticket and asking to let their email through would not be much of an issue, if this ever happens.

[woodruffw]

> Have you known of a case where a large institution sends a legitimate email to a small provider, the small provider rejects it, and the large institution does nothing about it?

It's usually the other way around, in my experience: I'm sending something from a relatively small provider (or a institutional mailserver), and it's rejected (sometimes silently) by a larger receiver. The reasons tend to be opaque, and support is nonexistent (presumably because the overwhelmingly amount incoming mail is illegitimate).

It's a hard problem, and the reality is that Google has made the average user's email experience radically better. But the drawback of that is that they rule the ecosystem by fiat, and that there are relatively few entities that can play keep-up with Google's (unpublished?) standards for reliable delivery. Getting booted out of Gmail increasingly means being left out in the cold, especially as institutions (like the company I work for!) use GSuite for mail.