How to check the domain zone in a line with email?

Question

PHP

Hello.
Please help me compose a regular expression for filtering the domain zone of outgoing e-mail's users.
First, I define an array with valid domain zones:

$allowedDomainZones = array(".ru", ".com", ".info", ".org", ".net"); // etc.

Then comes the check:

$invalidEmail = "[email protected]"; // e.g. define invalid string with email
$regularExpression = "^[a-zA-Z0-9_.+-][email protected][a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+$"; 
if (preg_match($regularExpression, $invalidEmail)) {
     echo $email . " email accepted! Ok =)";
} else { 
     echo $email . " you have entered invalid email =(";
}

Question: how to add a check of domain zones from an array to a regular expression $allowedDomainZones?
General task: to prevent registration of users who specify a domain zone outside

$allowedDomainZones = array(".ru", ".com", ".info", ".org", ".net");

domain zones.
We are talking about an information portal that used to work on Dupal 6, as a result of the lack of filtering, the database is frankly polluted by spammer accounts, accounts with a login like: admiN, ADMIN, ♥ My honey ♥ and other rubbish in ASCII.

Answer 1

And it is possible to be curious about the general task? At which time of New gTLDs is a whitelist of first level domains required?

$regularExpression = "^[a-zA-Z0-9_.+-][email protected][a-zA-Z0-9-.]+(".join('|', $allowedDomainZones).")$";

Answer 2

You can't expect email to have any format. We can only say with the statement that these are two lines in which there is no space, separated by @, in the right of which there must be at least one dot. There are hundreds of top-level domains, and there are also hit addresses. Some characters in the username may be ignored by a particular mail server, so it is possible to register several accounts for the same mailbox.

Answer 3

Never check e-mail addresses against RFC standards .