Keeping track of down Package Servers can be a challenge, especially in a large global environment such as what I work with on a daily basis.  Complicate this by the fact that over 70% of our total PSes are running on standard WinXP desktop PCs at rural sites and you have a lot of work on your hands!  So, I came up with the attached Notification Policy that emails in the case where a PS hasn't updated configuration in more than 4 hours (we use an hourly configuration request for our PSes).  The number can be changed easily in the "Edit Parameters" section of the Notification Policy.