Step 1: Verify the account is not over quota
Step 2: Check to see if message was sent to the Junk-Mail folder
Step 3: Send test messages from both an internal account and an outside account (ie. Gmail, Yahoo!, etc)
Step 4: Check for problem in the bounce back message
Step 5: Verify the correct email address is on the account and is spelled correctly
Step 6: Verify the MX records are pointed to mail.bluetie.com