Automatically generated emails usually don't get saved.

these emails don't usually get copied to local outbox folder (as any oher auto generated emails)

password may end up in cache somewhere tho....
and this is why it's a bad idea and rarely done nowadays

Generated emails usually don't get saved, as soon as it is delivered it will be gone.

I find that very hard to believe. While it is less common nowadays, many, if not most, mailing list and forum software sent passwords in plaintext in emails.

A lot of cottage industry web apps also did the same.

Idk if I'm misremembering, but it's my impression that they did this a lot in the 2000s, haha. I guess bad practices have a habit of sticking around

I've had service providers physically mail my own password to me before. Just crazy.

Always use unique passwords for every site.

passwords are usually hashed server-side tho and that's done for a reason.
if handling passwords correctly, server side hashing is way more secure then client-side. (with client side hashing, hash becomes the password...)

Is it though? While it certainly isn't something I'd recommend, and I've encountered it before, if E2E encryption exists we cannot assume a data exposure had occurred.

What they do on the backend has nothing to do with this notification system. Think of it as one of these credentialess authentication systems that send a 'magic link' to your inbox.

hashing on client side is considered a bad idea and almost never done.
you actually send your password "in plain text" every time you sign up.

Of course. You receive the password in plain on account creation, do the process you need, and then store it hashed.

That's fine and normal

Um. Yeah, because you provided it to them. They have to have it in plain text in order to hash it.