Re: sendmail behind a NAT-firewall ?

peter pilsl wrote:
> I just want to setup a portforward from the firewall to port 25 on the
> internal mailserver, which is fairly easy and should do the trick.

Yes.

> i) can I configure sendmail, so it announces as a different name than
> the local hostname ?? (mailserver.local does not look so good in the
> sendmail greeting-dialog and it will not resolve to the public IP)

Yes. For example by specifying:
define(`confDOMAIN_NAME', `your.fqdn.here')

> ii) Is my setup more likely to be my outgoing emails (my sendmail also
> acts as smtp-server for the other machines in the LAN) marked as spam by
> other mailservers ??? imho the setup should be quite straight and
> outside computers shouldnt even notice that sendmail is running
> somewhere inside beside one additional header that has a private IP.

Depends on the IP-range you are coming from. If it looks like a dynamic-pool
the answer is "Yes".

> iii) Is there something else that I miss? I dont ask in the
> network-forum, cause the technical part is quite clear to me. Question
> is only if I miss something vital on the effects to sendmail or how
> other see my emails. I setup quite a few sendmails, but always as
> standalone, or in a DMZ or directely on the firewall, but never on a
> server which is completely behind the firewall.

You my also consider incoming ident-requests ('reject', not drop them
at the NAT-BOX, or forward them inwards also); you may also think about
the outgoing ident-request because the IP/Port tuples don't match anymore
when you are not using 1:1 NAT.

cu
Clemens.
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