Python 2.3.4, Berkeley db 1.85, db file format not recognized

[Dan M]

I'm working on a script that will interface with sendmail on my FreeBSD
box. I'm trying to read my access.db file (yes, it's for a quick and dirty
SMTP-after-POP application). I'm trying:

import bsddb
bsddb.hashopen("access.db")

but I get:
bsddb._db.DBInvalidArgError: (22, 'Invalid argument -- access.db: unexpected file type or format')

This suggests to me that my bsddb is too new. I really don't want to
rebuild sendmail with a more current db, as I'm afraid of breaking
sendmail. Any suggestions on how to read this file?
 
FWIW, "file access.db" returns "access.db: Berkeley DB 1.85 (Hash, version
2, native byte-order)"