
First of all, you created this as a standard workflow rule and not a scheduled one correct?
This should run immediately. Within a minute or two seconds of you creating the project you should receive the email.
Did you enable the rule after you created it?
Lastly, I would recommend putting some tokens in your email to make it more useful. For example:
Subject: Project: {$Name} has been created and is Due on {$DueDate}
If you are still having issue Rich, just shoot me an email and I can investigate with you today. Thanks!