This is a little off topic of Courier per se ....

If someone can point me in the right direction for FAQ's or HOWTO's ...

Presently I use NIS for unix username/password distribution, Radius using MySQL, and some authuserdb stuff for Courier.

What I need to know is, what good is LDAP? PAM? And which combination of these is best for a fault-tolerant, distributed password system which would support unix logins, ftp, radius, Courier, etc?

Key words being fault tolerant, distributed, and one administrative interface? Am I asking the impossible?

Here's what I have to deal with now:

1: /etc/passwd for unix logins, ftp 2: MySql for radius 3: authuserdb for virtual users for Courier 4: Rely on NIS to share /etc/passwd for multiple unix boxes

The administration of these is driving me crazy, and if NIS goes down I'm screwed.

Thanks for any input!