In Outlook, Tools> Options> Mail Setup tab> under Send/Receive:
check the box: Send immediately when connected
Click the button Send/Receive and set a time in minutes that you want to automatically
send/receive mail.

If those options are already configured you mave have a damaged Send/Receive group within Outlook. To correct this follow these instructions. http://support.microsoft.com/kb/3123...d=2520&sid=228