Macro required to send a specific email after a date has passed

[philiasfogg]

My company are using the attached quotation book to record our quotes.
the RFQ tab records all requests for quotes. this is filled in for all quotes and includes a date that the quote needs to be returned by.

when we send the quote we fill in the date the quote was sent.

I need a macro that will send out an email if a submitted date hasnt been filled in and it is 48 hours before the due date. Then another email would be required when it is 24 hours before. and finally when it is the day it is due.

The email needs to go to the email address for the people listed in account manager and estimator as well as to 2 other speciefied email addresses (managment).

This is because unfortunatly some staff are forgetting to do quotes and the managment want to know if quotes arent being done. They want it automated so they are not reliant on anyone checking the workbook.