Harvesting email addresses from mail folders


Outlook version
Outlook 2010 32 bit
Email Account
Exchange Server
Outlook 2016 desktop connected to Office 365

I have a structured folder system where one of my product brands has a folder and every customer (by company) has its own sub-folder.

I'd like to select the product folder and have a method of searching through all sub-folders to harvest the email addresses in the from and CC fields in order to be able to mail each person with an important update about their product.

So far the built-in export only works on a single folder.

Any thoughts, please?