Consider the following scenario. You send a Multipurpose Internet Message Encoding (MIME) email message by using Exchange Web Services (EWS) in a Microsoft Exchange Server 2010 environment. The Content-Disposition header is set to inline. In this scenario, the inline contents disposition may be removed. Additionally, the attachment does not display as "inline" with the email message body on some clients.
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.