Can u3t9cb3j9zzmfqnea.tk receive emails?
No, u3t9cb3j9zzmfqnea.tk cannot receive emails because
it has neither an A record nor MX records.
Should you allow users to sign up to your website using the domain u3t9cb3j9zzmfqnea.tk?
No, u3t9cb3j9zzmfqnea.tk is a throwaway domain and
should be blocked.
How to block the disposable domain
You can use MailCheck's
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