[Techtalk] Any postfix experts out there?

[Maria McKinley]

Hi there,

I am having a hard time wrapping my head around postfix. I have set up a 
second ip on my mail server. The idea is to use one ip smtp for local 
use, so it doesn't get checked by the spam filter, and one ip smtp for 
use by the rest of the world. I can't seem to get the master.cf and 
main.cf files set up correctly, however. I don't know if it is a 
confounding factor that I am using NAT.

So, what I want mail.shadlen.org to receive mail from the world, and 
smtp.shadlen.org to be what users send mail from.

What I have currently, seems to be working, but I have a user 
complaining that some emails to him are not showing up, and looking at 
the config files, I don't think postfix should be working the way I want 
it to.

So, I was under the impression from this how-to

http://www.seaglass.com/postfix/turning_off_body_checks.html

That I should add this line to the main.cf file
inet_interfaces = mail.shadlen.org

and I think this should be for master.cf:

mail.shadlen.org:smtp   inet    n       -       n       -       - 
smtpd
   -o content_filter=sfilter:
mail.shadlen.org:587    inet    n       -       n       -       - 
smtpd
smtp      inet  n       -       n       -       -       smtpd
smtp.shadlen.org:587       inet  n       -       n       -       - 
  smtpd
   -o receive_override_options=no_header_body_checks

(A related question is whether I need to add the -o option for both port 
25 and port 587. This wasn't done in the original config, which I did 
not set up, but I'm not sure why.)

But, when I try to implement this, I get:

  fatal: bind 10.208.108.14 port 25: Address already in use

I should add that, everything use to come to smtp.shadlen.org 
(10.208.108.13), and that the new address is 
mail.shadlen.org(10.208.108.14). I have tried the main.cf file with both 
the hostname as mail.shadlen.org and smtp.shadlen.org, and neither works 
with the other changes. I have both ip addresses listed under 
proxy_interfaces.

What am I not understanding?

thanks,
maria