Each of the Purchase Orders contains links to despatch an order you can also despatch an order by clicking the icon in the despatch column.
The despatch order page is accessible by both your supplier and you. However when logged in as an administrator you have an option to turn off the notification to client.
The despatch notification contains all the tracking information that was entered at the previous page.
All despatch notifications have either a normal or a PAID status invoice attached depending on payment status.