Here on the Outlook team we’re always listening for feedback from users like you. We know that some customers on Office365 have had difficulty getting their mail when their passwords expire, and we wanted to help you avoid that problem. We have released an update for Outlook 2010 and Outlook 2007 that allows you to see a notification when your password will expire soon. More importantly, this notification will link directly to the Office365 page where you can change your password.
Download the update for Outlook 2010
Download the update for Outlook 2007
Read more at source: http://blogs.office.com/b/microsoft-outlook/archive/2012/09/19/password-expiration-notifications-in-outlook.aspx