BCC email to subscribers

with the 4th parameter of wp_mail() you can extend the header of the Email. So you can use BCC there. This should work:

<?php
    $bcc="Bcc: ";
    $i = 0;
    foreach( $emails as $email ){
        if( $i != 0 )
            $bcc .= ', ';
        $bcc .= $email;
        $i = 1;
    }

    $headers[] = $bcc;
    wp_mail( '[email protected]', 'New entry!', $body, $headers );
?>