> - smtp-auth-relaying: useful for big lan with some external users
> - smtp-after-pop: vpopmail feature that do this is good for small traffic
> network, but when you have 100 or more concurrent connection to the pop3
> you cannot use binary file but you must use a database.
I just use vpopmail and tcpserver here. Was that insufficient for your needs
or does the method you describe offer something more/different? I have quite
a few concurrent pop3 users (maybe 50-70, not 100 [yet]) and maybe half of
that in IMAP sessions but haven't run into any problems with tcprules.
Mind you I'm using courier-pop3d and courier-imapd instead of qmail-pop3d.