When you are working within your email client, (e.g., Outlook), you may receive an error message when you try to open the Delivery Slip for a given message by pressing the Delivery Slip buttons on the email2 toolbar (Tracking, Details, etc.).
This could be caused by a temporary connectivity problem between your email client and the service. If this is the case, just give it a couple of seconds and try again. Microsoft has acknowledged a problem with the .Net infrastructure that can cause this type of error.
It is also possible that the service is experiencing a different type of problem: it could be in the process of being updated, or it could no longer be available.
Regardless, in the event that the Delivery Slip cannot be displayed, the email2 toolbar will stop the browser window from launching, which will prevent further error messages.
