Disable account registration by anonymous users

If you don't need the functionality, that anonymous users can register accounts, I strongly recommend to disable it. This will save you the time to handle unwanted requests. You can change the setting under Configuration > People > Account Settings in the section "Registration and cancellation". Who can register accounts: Change from "Visitors, but administrator approval is required (default) to "Administrators only".

Drupal Account Registration and Cancellation

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