[Mailman-Users] Filtering mail for mailing list on separate mail server

[Alois Treindl]

I want to setup mailman for a public mailing list.

It should run on a special server (host B) located in the DMZ of our 
company.

The mail server (host A) of our institution runs inside the firewall, 
and cannot run a public http server. Also, no NFS mounts can be made 
between the mail server A and the 'mailman' host B.

Currently, host A is configured as 'smart host' in B's sendmail 
configuration. B does no mail handling by itself, and has no 'users'.
All mail, if any occurs,  is forwarded to A for handling.

We have extensive spam and virus filtering setup for the mail server 
host A, and I want to use this also for mail coming into the mailing list.

i.e. A should be the recipient for all mail (list submissions, list 
management requests) for the mailman mailing lists, should process it 
through its spam and virus filtering, and then forward it to the mailman 
host B for processing by mailman.

I have currently no clear understanding how I need to configure
- sendmail on both, A, and B, to make this work
- mailman on host B, to hide the origin from B in all outgoing mail 
addresses (it can be visible in the Received headers)

Where do I find advice or HOWTO information for such a setup?