Consider the following scenario:
- You have an AS2 message in BizTalk Server.
- You clear the Request asynchronous MDN check box in the Message Disposition Notification (MDN) settings.
- You select the Use agreement settings for validation and MDN instead of message header check box in the Validation settings.
- You do not remove the URL in the Receipt-Delivery-Option (URL) option.
In this scenario, BizTalk Server continues to send AS2 messages as asynchronous MDN instead of synchronous MDN.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.