PHP verifies the validity and correctness of the email entered by the user_PHP tutorial

　function validate_email($email){

　$exp="^[a-z'0-9]+([._-][a-z'0-9]+)*@([a-z0-9]+([._-] [a-z0-9]+))+$";

　if(eregi($exp,$email)){ //First use regular expression to verify the validity of the email format

　if(checkdnsrr(array_pop(explode("@",$email)),"MX")){//Use checkdnsrr to verify the validity of the domain name part of the email

　return true;

　}else{

　return false;

　}

　}else{

　return false;

　}

　}

Note: The checkdnsrr function is invalid on the win host! The following is a solution proposed by a foreign programmer. He also wrote a function to replace the checkdnsrr function:

　function myCheckDNSRR($hostName, $recType=''){

　if(!emptyempty($hostName)){

　if( $recType=='' ) $recType="MX";

　exec("nslookup -type=$recType $hostName", $result);

　foreach($result as $line){

　if(eregi("^$hostName",$line)){

　return true;

　}

　}

　return false;

　}

　return false;

　}