I just got this working (on FreeBSD 6.2). Whew! I set up my system using the Vanemery.com qpopper page as a guide.
I had originally put all my users into the APOP db, but that confused Qpopper when a PC user on OE tried to connect. So I deleted the PC users from the APOP db (leaving the Mac users in, since both Eudora and Mail.app do APOP), and that left me with a PAM error ("pam_authenticate returned 9").
Turned out that all I needed to do was reset the PC users' passwords, and then PAM noticed whatever it needed to notice, and everything's working now.
I also learned that pam.d/* replaces pam.conf, so I didn't really need to go looking for a "missing" config file.
-Walter
