/**
 * 正则表达式检查邮件地址
 *
 * @param 
 * @arrange (512.笔记) jb51.cc
 **/
function checkEmail($email) 
{
   // Create the syntactical validation regular expression
   $regexp = "^([_a-z0-9-]+)(\.[_a-z0-9-]+)*@([a-z0-9-]+)(\.[a-z0-9-]+)*(\.[a-z]{2,4})$";
 
   // Presume that the email is invalid
   $valid = 0;
 
   // Validate the Syntax
   if (eregi($regexp,$email))
   {
      list($username,$domaintld) = split("@",$email);
      // Validate the domain
      if (getmxrr($domaintld,$mxrecords))
         $valid = 1;
   } else {
      $valid = 0;
   }
   return $valid;
}


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