Having an AS2 port setup in an orchestration is easy to configure a one-way send port. However, configure a request-response send-port is a bit tricky. You probably know the message schema of the send port but you have no idea of the schema of an MDN.
You may attempt to use System.Object, System.String, or even create an MIME message type with two parts. However, none of these options work. Going through the schemas under the BizTalk EDI Application in Administration Console, you only see the property schema of EdiIntAs.EdiIntProperties and no sign for other schema for MDN.
At this moment, you will want to have a type that receiving any message. Microsoft.XLANGs.BaseTypes.Any is the savior. You can choose it from Schema > Select from referenced assembly...
