Mailserver and seperately Listserver in one Network with IP-Masq

[Michelle Konzack <linux4michelle@freenet.de>]

Hello, 

Currently I have no problems but maybe if I get my ADSL with fixed IP 
and IP-Masquerading. 

Following:      I have a local network with a virtual Web-Server which
                serves the domain linux4michelle.net and has additional
for each host (woody, potato, slink, dof) a Mailinglist. Then there is 
a Mailserver mail.michelle-is.de (exim 4.14) in my network. Generaly it 
handles the full mail-delivery in my Network and catch the Messages 
from 56 external Mail-Accounts like this one. 

Question:       If I get my my ADSL with fixed IP, can there be a 
                problem with the two Servers ? 

If yes, how must I configure my Servers that it works ??? 

I have seen, that others use the MAIN Mail-Server as the Server which 
connect to the outside of the Network and all traffic must pass it. 
Also the Listserver traffic. 

How can I do it ?

Thanks
Michelle