[SunHELP] Mail bounce problem

[Javier O. Augusto]

On Tue, 2002-04-09 at 10:40, Matt Braun wrote:
> Hey all.
> 
> I'm having trouble with some, but not all, outbound and inbound
> mail. When mail is sent to us from certain external sites (erols being one
> of them), it bounces. When we try to send mail to them we get:
> 
>    ----- The following addresses had permanent fatal errors -----
> <vahfma at external.com>
> 
>    ----- Transcript of session follows -----
> ... while talking to mx.mail.rcn.net.:
> >>> RCPT To:<vahfma at remotesite.com>
> <<< 550 cannot route to sender address <mjbraun at internal.com>
> 550 <vahfma at external.com>... User unknown
> 
> This is on a Solaris 8 box running Sendmail version 8.9.1
> 
> The mail server has a private ip address and is behind a firewall
> (fire.internal.com). The firewall's IP is in the MX record for
> "internal.com" but it forwards port 25 to
> the actual server "triumph.internal.com". In the sendmail.cf for triumph,
> masquerading is enabled as "DMinternal.com". Users are using Outlook to
> send and receive mail internally, and it's the only mail server.
> 
> 
> Note: I am not the designer or builder of this network; I just get to fix
> it.
> 
> What could be going wrong here?

I think you shouldnt be masquerading since your firewall is
portforwarding requests on 25 to your internal server.
that's my 5c tip.

javier