allow/deny pop3

[GARGIULO Eduardo INGDESI]

Hi all.

Is there any way to pass a "-x" paremeter file to tcpserver for allow/deny
pop3 connections. I was using qpopper from inetd and used hosts.* files
to do that work. Now, I'm using qmail-pop3d from daemontools and I'm 
looking for some /etc/tcp.pop3 file to restrict connections based on
IP addresses.
If it's possible, which is the format of this file?

--ejg:wq!