I have placed several test orders. Why do I not receive e-mail notification?

Two common causes:
First, you may not have a valid mail server setup in the fulfillment module. Check with your host to find out what should go there.
Second, the mail server is filtering out messages with the same address in the from/to fields. Use a different e-mail address when placing test orders. Something like 'testorders@yourmailserver.com' works well.