This guide has four accompanying samples, covering all of the scenarios described in the book: a typical on-premises application, the first migration to Windows Azure and subsequent optimizations.
It is instructive to compare code from the previous edition of my book to see what changed between Outlook 2003 and Outlook 2007 as well as the changes to the add-in model between VSTO 2.0 and VSTO 3.0. This is a VSTO Outlook add-in that handles the ItemSend event and checks if there are more than 25 recipients to warn you that you are sending to a lot of people.
See original here:
Changes in the Add-In Model between VSTO 2.0 and VSTO 3.0