central usermanagement

["daniel meier" <maillist@krims.ch>]

hi there

i'm just thinking about a kind of central user management. i'm a newbie
central usermanagement on linux. as far as i could find out there are 
two possibilities kerberos and pam.

I'd like to use this for:

ftp (proftp)
www
exim-smtp
courier
samba

for my needs (small company - 25 users) - I need a simple but powerfull
solution. I thought of using postgres with pam.

now I have two questions:

1.) is this the "right" way to go?
2.) is pam included in the binary-build-package of exim (woody).

thx.

kind regards

daniel