Flarum\User\Throttler  

EmailActivationThrottler

Unactivated users can request a confirmation email, this throttler applies a timeout of 5 minutes between confirmation requests.

EmailChangeThrottler

Users can request an email change, this throttler applies a timeout of 5 minutes between requests.

LoginThrottler

Limits failed logins, so passwords can't be guessed at full speed.

PasswordResetThrottler

Logged-in users can request password reset email, this throttler applies a timeout of 5 minutes between password resets.