Problems with Email Checker

SORRY, FORGOT TO INCLUDE [COLOR=red]PHP[/COLOR] in THREAD NAME!

here is my function which is in my functions.php file, every email i try, it says is not valid, even emails that should be valid, i’ve tried everything, i coulnd’t get it to work, any tips would be helpful. here is my emailCheck function…

function checkEmail($email) 
{
  $email = mysql_real_escape_string($email);
        $query_emailcheck = "SELECT email FROM hfs_users WHERE email = '$email'";
        $result_emailcheck = @mysql_query($query_emailcheck);
        $num_sameemail = @mysql_num_rows($result_emailcheck);
 
        if ($num_sameemail> 0) {
 
            $errors[] = "This email is being used by another user.";
 
 } if(eregi("^[a-zA-Z0-9_][email protected][a-zA-Z0-9\-]+\.[a-zA-Z0-9\-\.]+$]", $email)) 
  {
  list($Username, $Domain) = split("@",$email);
  if(getmxrr($Domain, $MXHost)) 
   {
  $errors[] = "Email address is invalid.";
   }
   else 
   {
      if(@fsockopen($Domain, 25, $errno, $errstr, 30)) 
      {
         $errors[] = "Email address is invalid."; 
      }
      else 
      {
         return FALSE; 
      }}
   }}