Sending messages from excel worksheet to specified email addresses.

I am trying to improve the my Excel data files by getting automatic messages for the due dates of orders we receive. The closing date for the tenders are to be sent to a specified e-mail address as a reminder, say 10-5 days before the due date.

The other option is sending e-mails again reminding the number of days left for the delivery of the goods from the manufacturer. I can determine the number of dates by using the Excel formula already. I would like to get a reminder about the days left so that we can remind the same to our suppliers. In this case I may need 2 reminders for 10-5 days before due date.

The program should check the date when the PC is on without the need of opening the Excel data sheet. We usually keep the these files on our desktop.

PLease check and advise if you can help me with this,

Regards
Fatih Atikol