installer/config.php
@@ -574,7 +574,8 @@ $mdn_opts = array( 0 => 'ask the user', 1 => 'send automatically', 3 => 'send receipt to user contacts only', 3 => 'send receipt to user contacts, otherwise ask the user', 4 => 'send receipt to user contacts, otherwise ignore', 2 => 'ignore', );