Tak mi to nedalo, a script jsem vyzkoušel
Struktura DB: email (varchar 100 cp1250) a id (int8,autoIncrement,unique)
Tento kód, a vše OK!

<?php
if (isset($_POST["ok"])){
error_reporting(E_ALL);
$dbhost="*****";
$dbusr="*****";
$dbpassw="*****";
$dbname="*****";
mysql_connect($dbhost,$dbusr,$dbpassw);
mysql_select_db($dbname);
$dotaz=mysql_query("SELECT mail FROM novinky");
$pocet=mysql_num_rows($dotaz);
echo "<p class='nadpis'>Databáze obsahuje celkem: ".$pocet." záznamů.</p>";
while($polozka=mysql_fetch_array($dotaz)){ 
$predmet=htmlspecialchars($_REQUEST["predmet"]);
$zprava=htmlspecialchars($_REQUEST["novinka"]);
$subject="Novinky z Smycmaweb";
$message="
<style type='text/css'>
.text {
text-align: left;
Color: #000066;
font-family: verdana, sans-serif;
font-size: 12px;
font-weight: bold;
text-decoration: none;
}
.text_c {
text-align: left;
Color: #BC0000;
font-family: verdana, sans-serif;
font-size: 12px;
font-weight: bold;
text-decoration: none;
}
</style>
<p class='text'>Novinky z Smycmaweb</p>
<table>
<tr>
<td width='120'><p class='text'>Co nového:</p></td>
<td><p class='text_c'>".$predmet."</p></td>
</tr>
<tr>
<td width='120'><p class='text'>Zpráva:</p></td>
<td><p class='text_c'>".$novinka."</p></td>
</tr>
</table>";
$headers="MIME-Version: 1.0\n";
$headers.="Content-type: text/html; charset=windows-1250\n";
$headers.="From: Smycmaweb\n";
if(mail($polozka["mail"],$subject,$message,$headers)){
  echo"<p>Na email <i>".$polozka['mail']." </i> byly odeslány informace o novinkách</p>";
}
}
echo "<p class='nadpis'>Novinky rozeslány</p>";
}

?>
<form method="post">
<input name="predmet" value="Testovací">
<br>
<input name="novinka" value="Novinka">
<input type="submit" value="ok" name="ok">
</form>