I have a user with a client application that creates an email durning processing. Once the client sends the email from within the application it uses a non email server that has an XML-SMTP file to transfer the email through the Exchange server to the internet for delivery. If the user creates the email and sends it to another user within the organization the email is delivered without issue. If the user sends the email to a customer on the internet it is bounced back without being delivered. Any ideas would be greatly appreciate.