Identifying packages missing from a distribution point
From the archive (2009). Written for the tools of the time, so some details may be out of date.
You can use this quick query to find any packages that are missing from one of your DP’s. This is quick way to find out if you simply forgot to distribute a package to a DP, or if there is something else keeping it from distributing. If you resend it to the DP and it still doesn’t show up, then you might need to do some further investigation into the logs and inboxes.
Here is some more in-depth information from Matt Broadstock’s blog.