Assume that you are using Microsoft BizTalk Server. You use the Multi-purpose Internet Mail Extensions (MIME) decoder pipeline component in your own receive pipeline to receive a multi-part MIME-encoded message. In this scenario, the MIME/SMIME decoder in the MIME decoder pipeline component selects an incorrect message part as the BizTalk message body part.
This issue is fixed in the following cumulative updates for BizTalk Server:
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.
For information about the service packs and cumulative update list for BizTalk Server, click the following article number to view the article in the Microsoft Knowledge Base:
2555976 Service pack and cumulative update list for BizTalk Server
For more information about BizTalk Server hotfixes, click the following article number to view the article in the Microsoft Knowledge Base:
2003907 Information about BizTalk hotfixes and Service Pack support