Ragazzi, ho risolto.

Posto l'intero codice magari possa servire a qualcuno.

Codice PHP:
$elenco = array();
$array=explode("\r\n",$_POST['textarea']);

$count=0;

foreach(
$array as $row['campo'] ) {

$campo=$row['campo'];
    
$querymysql_query("SELECT email FROM email WHERE email='$campo' ");
        
$email=mysql_fetch_array($query);
        
//echo $email[0]."+++++++++++++
";
            if(
$email[0]!=""){
            } else {
                echo 
$row['campo']."";
                
$a=mysql_query("INSERT INTO email (emailVALUES(\"$campo\")") or die (mysql_error());
                
$count=$count+1;
            }        
unset(
$campo);
unset(
$query);
unset(
$email);