Is it possible to check mail for existence?

Question

PHP

All good.
I thought about the "reputation" of my server for mail services. Now, if there is such a "parasite" that will specifically send a registration request to a non-existent address, suppose [email protected], then mail can be added to the black list. I rummaged through the Internet, tried to find at least an implementation, a semblance of this and this , I just found nothing interesting and working. What can you suggest?
PS Regularly check for the correct format (dog, dot between domain levels) is too small.

Answer 1

Can. But there are no guarantees that you were told the truth. It is for the purpose of protecting against spammers that I can say to an existing address that it does not exist (but still accept mail and deliver it to the address), and to a non- existent one - that it exists and accept mail in / dev / null.

Answer 2

Another pursuit of imaginary problems.
They write to you in Russian, the server does not disclose whether the account exists. What is not clear about this sentence?
For an attempt to send to a non-existent address, no one adds to the black lists.
Not to mention that if you follow your logic, then you will still get in, because checking the address is all about trying to send a letter.
And the "reputation" is maintained by completely different means, and not by random body movements based on night fantasies