If I understand you ok, you used an exported ldif file from netscape to
setup all your existing mail accounts to qmail/vpopmail, right?
Using ldap as auth engine on vpopmail's ldap module, or local userdb files?
-- no, just mysql as storage
You imported your cyphered SHA-1 strings from netscape database, ok.
Then, once inserted in vpopmail users database, vchkpw and authdaemon
recognize such SHA-1 strings to validate users' passwords?
-- yes, some vpopmail code was modified to support this format.
so you can have sha-1 passwords & md-5 passwords at the same time.