I'm going to quote my old comment here:
Afaik, you can't block the entire instance yet, although some frontends or apps gives you ability to do that
There is an open request talking about it:
martinbasic
joined 1 year ago
Just look around the repository, I think your situation might similar to issue 3757
https://github.com/LemmyNet/lemmy/issues/3757
Quote:
[...]You're saying when someone requests their password 3 times it completely breaks email for the whole instance for 24 hours?
No just for that user for 24 hours
Wait 24 hours, then try to register again with different email. If no avail, you might need to ask the admin for help on the verification email issue.
Okay, thanks for pointing out. May be you can try to use a different email address, or using a plus address (helfrd0771+lemmy[at]gmail[dot]com in your case) if you want to use the same username.
For now, plus address are treated as different as regular emails. See https://github.com/LemmyNet/lemmy/issues/3864
Ref: https://github.com/LemmyNet/lemmy-ui/issues/1096, but I suspect it's implemented or not, better to wait 24 hours before you try
If it still doesn't work, I think it is better off to reach out the admin for help.
Try if you can login using your username and your password, then check in settings if you mistyped your email, if so, change it to verify your email again.
This method works about few months ago when I create my new account on other instance, don't know if this still works.
Also, as other mentioned - check your spam folder.
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