The 2011 babase file contains what was salvaged of the early years of the list after IT here had migrated the list to a different system.  I have no further information about this file.

The 20230630_babase_babaseannounce list contains all the files from the current Princeton listserv for both lists as of the date in the file name.
The compressed file contains six files (each list in Mac, Windows, and Linux format).
The output consists of individual files in ".eml" format. These files can be individually opened in any text editor, or can be imported into most email applications (Apple Mail, Thunderbird, Outlook, etc.) 
to allow easier reading and searching, and to allow access of any message attachments. Given that there are eleven years of data archived on both lists it is likely to a significant amount of data. 
Importing that volume into any email client will require a fair amount of time and patience. The email would need to be kept locally as most email services do not provide that much storage space.