Symptom:  Outlook will not automatically send or receive when you start it.  You must manually click Send/Receive.

Solution:  Outlook should by default send/receive after a few seconds after you start it.  Here are instructions for Outlook 2003; older versions will have similar settings.

1. Tools > Options > Mail Setup.
2. Check Send immediately when connected.
3. Click OK.
4. On the same screen, click Send/ Receive.
5. Verify that Schedule an automatic send/receive every is checked and has a reasonable time value there.  You do not want to check email every minute, use a value between 5 and ten minutes.
6. Click Close, click OK.

If you have a different version of Outlook, look for similar settings.  If Schedule an automatic send/receive or Check for new messages every (older versions) is not set, you must manually click the main page Send/Receive button each time to get your email.