[vPostMaster] Vpostmaster

[Sam Povilus]

Is this: http://www.tummy.com/Products/vpostmaster/genericdl.html 
current? Because i tried

      Dovecot configuration:

         Add the following lines to the end of the "/etc/dovecot.conf":

         #  vPostMaster Configuration
         default_mail_env = maildir:~/Maildir/
         auth_userdb = pgsql /etc/dovecot-pgsql.conf
         auth_passdb = pgsql /etc/dovecot-pgsql.conf
         first_valid_uid = 100

and it said

 Error: Error in configuration file /etc/dovecot.conf line 1020: Unknown setting: userdb

when I tried to start dovecot.

Sam Povilus