Yes David, I can´t see any reason why it would not possible. You would need to set an “uploadedpdfs” collection, where one of the field should be of type ‘document’. On adding a row to the collection, you would send an email. Now, this might take a while before you can give any kind of feedback to the user who just uploaded (“Document saved”), unless you take it outside the .when. But that could have its own problems.
Maybe it is not a bad idea to contemplate a cron-job on a hidden page that queries the database for a “emailsent” flag and does the email sending for you in the background every hour or so. It´s all documented, just look at the articles for sending emails and uploading docs. For cron, search this forum.