If the answer is YES then you will need to read the below....
As technology has evolved, we’ve developed new and better ways to access your e-mail, and it’s important to us that we provide you with the most efficient ways to do so. With that in mind, Hotmail is preparing to stop using the DAV protocol on September 1, 2009.
What does this mean? Well, if you currently access Hotmail using a desktop mail program like Microsoft Office Outlook, Outlook Express, or Entourage, you may still be using the DAV protocol in these programs, and you’ll need to take action in order to continue getting your Hotmail. We’ll be sending mail to customers who are likely to be affected to let them know what they’ll need to do. Here is a quick summary.
What is the DAV protocol?
The DAV protocol is a communications method that mail programs use to display your e-mail. Outlook, Outlook Express, and Entourage may use it to display your Hotmail.
full article at the Windows Live Teams blog here
with steps to make the transition to new system smoother