Implementing a Drag-and-Drop function from MS Outlook into our web application

Implementing a Drag-and-Drop function from MS Outlook into our web
application

Good morning,
We're looking for some development guidelines/assistance with respect to
implementing a Drag-and-Drop function from MS Outlook into our web
application (currently in development). Our ultimate aim is for our users
to be able to drag emails from their Outlook instance into our application
running in their browser. As it stands we're able to achieve this
functionality with a file (for example from the user's desktop) but not
directly from Outlook.
Our application is being developed using Visual Studio for PHP and an SQL
Server 2012 backend.
Our progress so far: • We have an HTML5 control on our page which receives
the javascript onDrop/OnDropStart/etc events and is able to enumerate and
retrieve the content therein, files or otherwise; • When dragging emails
(or other objects such as contacts) from Outlook (tested in Outlook 2010),
we're able to enumerate plain text data but not the MIME content of the
email (message or attachments) • We're able to enumerate and retrieve
plain text and HTML content of an email by Ctrl+A on the contents and
dragging that into the HTML control.
Where we need assistance is in understanding how to access and retrieve
the full MIME content of an email from the drag/drop events the browser
has access to. We're aware of the PIO package for Visual Studio which
would enable this for a local .NET application however we don't appear to
be able to use that for a web application.
As the product is in early development phase we're open to suggestions and
directions from Microsoft as to how we might best achieve this, including
if we can get this done using .NET or ASP controls for the web
application.
I look forward to your reply
Regards, Asanka