title: Please explain what an outlook add-in is
body: <p>Can someone give me a quick explanation of when I would use Visual Studio 2008 Outlook 2007 Ad-In project type? and how would that compare to developing a bunch of outlook macros directly in outlook?</p>
  
  <p>Basically, I want to have some sort of application read email (with attachments) from a pop3 email box, do some filtering/editing/validation of the subject/sender/content and then if certain conditions are met, save the attachments to a local file, and then add an entry into an SQL server database table (i.e. date/sender/subject/message).</p>
  
  <p>Seems there are at least 10 different ways to do this....so between an outlook macro and a VS Office Project, how do I pick?</p>
  
  <p>I am not clear, if I create this solution as a Visual Studio outlook add-in, where does it run? Is it loaded into outlook, does it run as a separate process and communicates back and forth with outlook? if outlook is not running, does it start it?</p>