Extract Emails to Grouped CSV

I have three separate Word files that hold roughly 250 email addresses in total. I need those addresses transferred into a single CSV. Please group the emails by the Word document they came from and label them “Document 1”, “Document 2”, and “Document 3” in a dedicated source column.

While collecting, remove duplicates that occur inside each individual group, but don’t compare across groups—each document’s list should stay independent of the others.

The finished deliverable is one clean, well-formatted CSV that I can open in Excel or import into any email platform without further editing.