excel 2007 automatic email notification

Hi, I need a help here. I have a workbook and I want it to send email notifications automatically when a contract is due for renewal (45days before expiry) and again on the date it expires. I've seen a couple of posts/questions here same as mine and I tried to the same but I always fail. I can't run it. I'm using outlook in the office. I attached my sample workbook. Thanks in advance.