Use the following function to validate the email address with valid domain.It returns TRUE on success and FALSE on failure.

Eg:
anbu_rajendran@yahoo.co.in is a valid email.

abc@abc.com is not a valid email.

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function email_validate($email) {
$isValid = true;
$atIndex = strrpos($email, "@");
if(is_bool($atIndex) && !$atIndex) {
$isValid = false;
}
else {
$domain = substr($email, $atIndex+1);
$local = substr($email, 0, $atIndex);
$localLen = strlen($local);
$domainLen = strlen($domain);
if($localLen < 1 || $localLen > 64) {
// local part length exceeded
$isValid = false;
} else if($domainLen < 1 || $domainLen > 255) {
// domain part length exceeded
$isValid = false;
} else if($local[0] == '.' || $local[$localLen-1] == '.') {
// local part starts or ends with '.'
$isValid = false;
} else if(preg_match('/\\.\\./', $local)) {
// local part has two consecutive dots
$isValid = false;
} else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain)) {
// character not valid in domain part
$isValid = false;
} else if(preg_match('/\\.\\./', $domain)) {
// domain part has two consecutive dots
$isValid = false;