I tried opening an address book folder with Max E. 5.5 and received the "selected address book folder has been acessed by a later version of Max" error message. What version do I need to open these records? Can Max 9 or 10 open these 6-8 year old address books? My Christmas letter is awaiting its mailing list.

It sounds to me like the address book/database has been converted/upgraded to work with a newer version of maximizer than 5.5. I would assume if you do have access to maximizer 9 or 10 to access this database that it will be able to read the data, possibly after another conversion of the addressbook to version 9 or 10.