Will the unique string be email and sha256?

Question

Hashing

I make links to confirm registration
Question if you receive a hash from e-mail without adding dates and other things, will it be unique?

Answer 1

The probability of a collision is extremely small, so we can say that it is unique.
The problem is different, if the receiving algorithm for the mail address is static and simple, then it is easier to pick it up. So they will be able to confirm registration without mail. I advise you to add a long "salt" to the address. Better yet, generate a random hash.