Automatically send emails with outlook based on dates

Hi all

I have been tasked with creating a "document review tracker", within excel.
The document reviews themselves are a 3-stage process, and the excel file will merely serve as a tracker to see where the documents are (i.e. who has them) and when their review is due.
I have completed the vast majority of a table/tracker, listing documents references, due dates etc. but need help creating a macro that will automatically send a reminder email when a "due date" is coming (i.e. within 3 working days) and when the "due date" has expired.
This is further complicated by the fact that I need a different email template for each of the 3-stages in the process, so I need 6 email templates, (a reminder and an overdue email for each of the 3 stages). I also want to include some of the data from the table in the email (like the document reference, due date etc.).
I want the macro to be run daily, but on user command.

I have created 6 "mini-reports", on separate worksheets, that extract all of the data, from the main "tracker" worksheet, that I need to be emailed. So it pulls the ones that due for a reminder and those that are overdue with, the users name, document reference, and due date, and uses a lookup to pull the email addresses from a separate list.

All I need now, is a macro that can automatically create the emails, from templates (also created), populated with the data in the "mini reports" and send them

Any help is much appreciated.