[NTLUG:Discuss] Making a spam shield server

[Chris Cox]

. Daniel wrote:
> Here's the scenario:
> 
> At the office is a MS Exchange 2003 server.  I would like to put up a  
> Linux box (got it loaded and just about ready to go) running CentOS 4.4 to 
> accept mail for the domain and forward it on to the Exchange server after 
> processing through greylisting and spam assassin's filters.
> 
> The problem is that I get a user unknown error.  So either I create users 
> manually (not gonna happen) or come up with a way to link the server to the 
> Active Directory domain via LDAP as a means of determining whether or not a 
> user exists.

This is actually quite easy.  Samba/winbind.  Of course, the server has
to be able to join the Domain (must have network visibility to it).
In openSUSE anyhow, you'll end up with the Windows users occupying uids
in the 10000+ range... likewise with Windows groups.  Looking at one
of our RHEL boxes... seem they start mapping at uid/gid 16777216+
(wow).  The smb.conf that comes with RHELAS4 is well commented (just
remember that comments count against you big time in Samba performance).
Hopefully you can figure things out from there.  If not... I can
probably zap you one from a working config I have.

This doesn't require an LDAP server on Linux (if you thought that might
be true).