Auto email on opening an Excel File

Hi
I am trying to create macro which goes through this two sheets and when the due date / expiry date is approaching, my idea is to create auto email before 10 days to the addressee mentioned in the column “O”. With the following macro, I am able to complete the task for only one sheet which is active sheet when I am opening the file. Can anyone help to accomplish my task so that it will go through all the sheets by name and generate emails to the addressee based on the due date. The structure of sheet shall be the same for all sheets.

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Thanks in advance.

Buvanamali

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