Here's the email text.
Thank you for your recent iPhone purchase at the Apple Online Store.
Unfortunately, due to a problem that affected a small number of orders, service to your current phone may have been disconnected.
To reinstate service on your current phone, please call AT&T Customer Service at 1-800-331-0500, or visit an AT&T store.
We apologize for the inconvenience this has caused. If you have any questions, please call us at 1-800-MY-APPLE.