Unable to send Outlook-Mail as an attachment while triggering a process through Email

Hi 

We are triggering a process through email with some attachments and it is working fine. But if we send an email as an attachment, it is not found in the process and if we have any attachments in side the email-attachment they are available in the process.

Here my requirement is, we have to show the email-attachment as a main attachment.

How can I achieve this functionality.

Regards,

Nageswar