How to check if an email address exists without sending an email?

Question

I have come across this PHP code to check email address using SMTP without sending an email.

Has anyone tried anything similar or does it work for you? Can you tell

Answer 1

"Can you tell if an email customer / user enters is correct & exists?"

Actually these are two separate things. It might exist but might not be correct.

Sometimes you have to take the user inputs at the face value. There are many ways to defeat the system otherwise.