I would echo what liteswitch said and suggest creating a test job with a simple step like SELECT '1' so you can run the job anytime. I would also go back through and double check everything (SQL Agent Alert System setup, operators, job notification) . This BOL article has the setup steps. http://technet.microsoft.com/en-us/library/ms186358.aspx

The most common issue I see is with people forgetting to restart SQL Agent which is why I suggested it earlier.