Outgoing Only mail server using Postfix
 

I currently have a central email server running MailScanner/spamassassin/postfix sending and receiving all email. I've setup and configured a new server intended to only send email. I do not want it to receive emails, only send them. I'm having difficulty configuring postfix to do this properly.

SLES 9
Postfix 2.1.1

I used the information in the Standard Configuration Readme on the Postfix site to configure the Null-Client setup. However, when setting inet_interfaces to the loopback address, I cannot telnet to port 25 from another server on the network, only locally, which makes sense, but how does it receive connections to send email if this is case? Therefor when attempting to send mail through this server it fails. If I set inet_interfaces to the IP Address of this server or to ALL, I begin receiving inbound email from other mail servers and they receive rejected errors.

/etc/postfix/main.cf:
myorigin = $mydomain
relayhost = $mydomain
inet_interfaces = 127.0.0.1
local_transport = error:local delivery is disabled

All email being sent is originating from a Lotus Domino server. We set SMTP server to the new IP Address of this outgoing only email server. Emails are received fine through the original email server, however we cannot send anything out. Does anyone have any experience setting up something similar?

Thanks!!