How to check if an email exists before sending an email?

Question

PHP

How to use PHP or through something that can be connected to php to check email for existence before sending? Many people enter the left email and they get an error when sending. I'm afraid you won't like it sendpulse.com has more than 10% errors.

Answer 1

I think that all the same the very first letter to confirm the box should go blindly. Well, then send out only to those who confirmed through the link from the letter ...

Answer 2

$email = $_GET['email'];

if (!(filter_var($email, FILTER_VALIDATE_EMAIL)))
        die('Неверно указан E-mail');

isn't that what you need?

Answer 3

The most reliable way to check for the existence of an e-mail is to call out by initiating an SMTP session. It will be enough to get 250 OK to the RCPT TO command with the address being checked.
But it's not 100% guaranteed because some servers always say OK to any address in the domains it supports.

Answer 4

No way.
As long as it is based on SMTP, anything can be specified. Yes, you can send a verification email. And on the other hand, there is greylisting, which will request a resend or, in general, an evil self-written script that also does a counter check - is there an address from which the letter came? This is an old rambler problem - letters to rambler.ru can get in a few hours (!) After being sent. Even the syntax is difficult to check - the syntax of the sender's address implies an insane amount of variations.

Answer 5

For Google
superuser.com/questions/207926/if-to-and-from-head...
For many mail servers it's the same.