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.
In this example we assume that the Internet domain name is
"example.com" and that the machine is named "nullclient.example.com".
As usual, the examples show only parameters that are not left at
their default settings.
myorigin = $
relayhost = $
inet_interfaces = 127.0.0.1
error:local delivery is disabled
8 Comment out the local delivery agent entry
Line 2: Send mail as "[email protected]" (instead of
"[email protected]"), so that nothing ever has a reason
to send mail to "[email protected]".
Line 3: Forward all mail to the mail server that is
responsible for the "example.com" domain. This prevents mail from
getting stuck on the null client if it is turned off while some
remote destination is unreachable.
Line 4: Do not accept mail from the network.
Lines 5-8: Disable local mail delivery. All mail goes to
the mail server as specified in line 3.