log contact info edits

I would really like to have a history of previous contact information. I suspected that the table crm_activity_history held that, but doesn't seem to be the case. (What does that table do? It's empty in my system).

Why I want history of edits to contact info:

1. Staff makes mistakes.
2. Find history of email correspondence in old email files.
3. Old addresses are a hint when a direct mail comes back undeliverable and I'm trying to re-locate an important donor. They are much more likely to have moved to the old neighborhood than anywhere else in US (except new neighborhood).