BizTalk SMTP Message Part Getting XML Encoding

I have a email multi-part message which I am using to send failed message routing from the messagebox to a business users mailbox.

Email{ Body - RawString; OriginalMessage - string};

The original message gets set from the received mess开发者_StackOverflow社区age that activates the orchestration. For example assume the original failed message is from a Flat file that failed disassembly with the contents:

Order,1,2,3,4,5,<6>,

I set the message using:

Email.OriginalMessage = MyUtil.XlangMsgToStringMethod(FailedMessage);// XmlDocument type, this can be malformed xml, valid xml, or flat file that fails in disassembler.

I can then write to the event log to test whats in Email.OriginalMessage:

System.Diagnostics.EventLog.WriteEntry("BizTalk Server 2006", Email.OriginalMessage, Information); // This displays the correct original message "Order, 1,2,3,4,5,<6>,"

When the email is delivered using a SMTP server and a dynamic send port, with the attachment set to text/plain mime type, the original message gets xml encoding escaped and wrapped in xml:

<?xml version="1.0"?>
<string>Order, 1,2,3,4,5,&lt;6&gt;,</string>

Any ideas why? The SMTP port has passthrutransmit as pipeline.

Thanks.

SMTP port is getting XMLTransmit forcing the message to be treated as XML. Switch to PassThroughTransmit.