Is there any software that would be able to extract email addresses and put them into an Excel spreadsheet?

My coworker at a magazine saved about 1500 emails from readers regarding a specific feature in the magazine. We’ve turned that feature into a book and would like to send a special email to those readers letting them know about the book. Is there any way to create a list of all those email addresses without manually re-typing all 1500 email addresses? if i have our part-time intern do it I think it might take a whole week.