In http://www.postfix.org/STANDARD_CONFIGURATION_README.html this text ...
A null client is a machine that can only send mail. It receives no mail from the network, and it does not deliver any mail locally. A null client typically uses POP, IMAP or NFS for mailbox access. ... is confusing (the part about POP, IMAP, or NFS). Can this configuration be used for a "null server" (I'm guessing this term)? This new server only needs to send mail. It has no access to the internet (though it does have access to the internal DNS caches and the real mail server via private IPs) so it won't be able to reach the MX host for recipients by means of the IP address it would get via MX and A lookups. It just needs to always forward everything via the primary mail server (or the secondary if not configured to have a send queue of its own). It won't receive or read any email (no POP, no IMAP, no NFS). -- sHiFt HaPpEnS!
