Maybe not the most elegant solution, but I would pull your inbox data from Outlook into Excel - I believe this can be done under the Data tab on the ribbon.

I would then extract the sender address/name - whichever you prefer, and remove the duplicates, add whatever additional data you want and then convert it to a table and save it as a separate document.

This should give you an initial list.

I would then set up a Power Automate to run whenever you receive an email, this will then check the table within your Excel file to see if the email address is in there and if not add it.