We are having an issue at work whereby each time a message is sent from any external source (the domain can be any) to an invalid address on our domain, for example, an old email or a miss-spelling, an NDR is being created but instead of being sent to the sender, it is sitting in a queue on our server. In the queue window, the Source for these messages is TLS and the additional information reads - The remote SMTP service does not support TLS.
We are running MS Exchange 2003, we do use TLS however, we have a separate virtual server and connectors which has this enabled. Can anyone suggest why this is happening? In the Default SMTP Virtual Server TLS is definitely unchecked.
Here is a picture of the queue itself;