[webmin-l] Postfix and locahost

[Mac <ma...@ay...>]

Hi,

As I have a site with 20.000 members I want to send them a newsletter  
from time to time. I have set up my own SMTP server on my computer  
with Mac OS X 10.4

The problem now is that I was reading that mail with "localhost" in  
the header is recognized as SPAM by many ISP's.

Is there a way to change "localhost" to i.e. the domain name of my  
site or my static IP address?

/Mats