I really can't fathom keeping correspondence in binders filed by addressee. How would you ever find anything, really? These were memos from the mid 80s. Still filed away in our file room as if there was really anything meaningful to be gleaned from them. As if the company hasn't drastically changed since then in size and focus. As if any of the people referenced are even still employed! As if our accounting system was still the same!
And so, things got packed into boxes and pitched into dumpsters.