Hi Patrick Thornberry,
Auctiva actually doesn't offer an option to automatically send your buyers an email when your items have been marked as shipped. However, when you print a shipping label through Paypal, I believe Paypal sends the buyer an email containing a tracking link that also says the item is expected by the carrier for shipment.
The only basic types of emails that can be sent automatically through your Auctiva account are winning bidder emails, thank you bidder emails, checkout complete emails. There is also a consignment notification email that can be sent if you are using our consignment tools.
If you have any additional questions regarding your Auctiva account, please feel free to contact our customer support team using the web form on the following page of our site:
http://www.auctiva.com/help/requesthelp.aspx-Mike