I recently came into possession a ticket from a user stating (as you will soon see) that she is recieving duplicate emails. While the issue itself isn't what makes the blog worthy, it's the way she handled it that does. Here is the email.
"Hi Enterprise Helpdesk – I am wondering if you can help me with a strange problem. I often receive duplicate emails from a wide variety of people. It seems to be a problem with Outlook. I have attached an example of duplicate emails to better explain my problem." In her emails are two attachments of the same email.