There is an issue with the nationwide Blackberry network at the present time. Some users may experience delays in mail delivery. Any mail sent to your Notes account will be queued on the VCU Blackberry Enterprise Server for delivery to your Blackberry handheld as soon as the Blackberry network is available.

From RIM Blackberry Support:

Symptoms you MAY experience: Blackberry users may be unable to send/receive messages or may have difficulty connecting to the network.
Estimated time of repair: Unknown

RIM Technicians are working towards resolution as quickly as possible. We apologize for any inconvenience that this may cause. Thank you for your patience as we work towards resolving this issue.