Blackberry not sending Emails

If you check the Application event viewer on the BES
Look for warnings or events similar to these

Event Type: Warning
Event Source: BlackBerry Messaging Agent WL-BES-01 Agent 3
Event Category: None
Event ID: 20400
Date:  28/09/2011
Time:  10:57:20
User:  N/A
Computer: WL-BES-01
Description:
LDAP path of account

MDB

Event Type: Warning
Event Source: BlackBerry Messaging Agent WL-BES-01 Agent 3
Event Category: None
Event ID: 20154
Date:  28/09/2011
Time:  10:57:19
User:  N/A
Computer: WL-BES-01
Description:
User username not started

Then check this URL...bes blackberry Kbase Blackberry KB Article

Arrange to possibly reboot the server so that services restart and connect to the Global Catalogue server in the AD