Hi @amitinait, thanks for the questions!
HTTP and DNS challenges are the only* methods supported by Let's Encrypt. I'm not entirely sure I understand what you mean by pre-validating domain owernship but I suspect the answer is that there is no way to do it.
The e-mail validation method you mention is particularly fraught and was avoided by design while standardizing the ACME protocol that Let's Encrypt uses for domain validation.
* - With the caveat that there is also a new TLS based challenge type available in the staging environment only.