Your instance admin can see it. It’s not public though.
if your worried getting spammed with emails, i’d suggest using an email relay in your Lemmy account instead of using your primary email add. Here is an example - https://relay.firefox.com/
email addresses aren’t even required for the accounts, so i doubt it travels the fediverse
Wait, I had to verify my email. Was there an option to not somewhere?
Email requirements for registration are set per-instance. Beyond that, it’s my understanding that only a user’s existence is shared across instances, in order to attach you to your content. Your registration details stay on the instance you belong to.
Anyone with access to the sql database can see it.
Who has access to the database?
It would be different in every instance. Generally the instance “owner” as I would call it. But also and developer that may have been given access.
People assume it’s admin. But as far as I can see, on my admin profile, I have no access to that data.
You need actual access to the server. Like ssh permissions