If you want to do it this way, you can base yourself on the following methods:
<?php
$email = \"abc123@somewhere\"; // Invalid email address
//$email = \"somebody@somesite.com\"; // Valid email address
// Set up regular expression strings to evaluate the value of email variable against
$regex = '/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/';
// Run the preg_match() function on regex against the email address
if (preg_match($regex, $email)) {
echo $email . \" is a valid email. We can accept it.\";
} else {
echo $email . \" is an invalid email. Please try again.\";
}
?>
or:
$string = "$emailtocheck";
if (preg_match(
'/^[^\W][a-zA-Z0-9_]+(\.[a-zA-Z0-9_]+)*\@[a-zA-Z0-9_]+(\.[a-zA-Z0-9_]+)*\.[a-zA-Z]{2,4}$/',
$string)) {
echo "Successful.";
}
or:
<?php
$email = "abc123@sdsd.com";
$regex = '/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/';
if (preg_match($regex, $email)) {
echo $email . " is a valid email. We can accept it.";
} else {
echo $email . " is an invalid email. Please try again.";
}
?>
Source: https://stackoverflow.com/a/13719991/1415724
or:
<?php
// check e-mail address
// display success or failure message
if (!preg_match("/^([a-zA-Z0-9])+([\.a-zA-Z0-9_-])*@([a-zA-Z0-9_-
])+(\.[a-zA-Z0-9_-]+)*\.([a-zA-Z]{2,6})$/", $_POST['e-mail'])) {
die("Invalid e-mail address");
}
echo "Valid e-mail address, processing...";
?>
Source: http://www.techrepublic.com/article/regular-expression-engine-simplifies-e-mail-validation-in-php/
Plus, you can try what André Daniel wrote as an answer as well. You have many choices.