[qualiteam]

In this case you should use the following form:

<form name="news_subscription" action="news.php" method="post">
  <input type="hidden" name="mode" value="subscribe"> 

  <input type="hidden" name="s_lists[]" value="1">
  <input type="hidden" name="s_lists[]" value="2">
  ...
  <input type="hidden" name="s_lists[]" value="[N]">

  <input type="hidden" name="skip_validation" value="Y">
  <input type="text" name="newsemail" size="30" value="">

  <input type="hidden" name="sl" value="en">

  <button class="button main-button" type="submit" title="Subscribe"> 
     <span class="button-right"><span class="button-left">Subscribe</span></span> 
  </button> 
</form>

Add all the necessary lists:

<input type="hidden" name="s_lists[]" value="[N]">

The list ID [N] can be found on admin/news.php (see the "targetlist" URL param for the corresponding news list).

Insert this code:

PHP Code:

if ($news_lists_num > 1 && $mode == "subscribe" && $skip_validation == 'Y') {
    $validated_emails[] = stripslashes($email);
} 


right before this line:

PHP Code:

if ($mode == 'view' || ($mode == "subscribe" && in_array(stripslashes($email), $validated_emails))) { 


in the "modules/News_Management/news_manage.php" script.