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Subject: Re: Is this possible with postfix?
From: Parkhaev Vladimir (vladimirteleglobe.ca)
Date: Fri Mar 03 2000 - 16:30:53 CST

On Fri, 3 Mar 2000, Wietse Venema wrote:

> Have the MX record point to the external host.
>
> my.domain IN MX 10 external.my.domain
>
> On the external host, use a transport map
>
> /etc/postfix/transport:
> my.domain internal.my.domain
>
> /etc/postfix/main.cf:
> relay_domains = my.domain
>
> On the internal host,
>
> /etc/postfix/main.cf:
> relayhost = external.my.domain
> mydestination = my.domain, internal.my.domain localhost.my.domain ....
>
> People with firewalls do this all the time.
>
> Wietse
>

Hm, if I am not mistaken, with MX record pointing to external host,
the flow of traffic will be as follows:

               +--------+ +----------+ +----------+
 Internet ---->| Public |---->| Internal |-------> | Internal |
          <----| SMTP |<----| SMTP | ------ | Client |
               +--------+ +----------+ | +----------+
                    ^ |
                    |_______________________|

Is there a way to route oubound trafic as folows:
InternalClient->InternalSMTP-> PubliclSMTP?

 
> Matthew Hagerty:
> > Greetings,
> >
> > Is it possible to accomplish a configuration like this with postfix:
> >
> > +--------+ +----------+ +----------+
> > Internet ---->| Public |---->| Internal |---->| Internal |
> > <----| SMTP |<----| SMTP |<----| Client |
> > +--------+ +----------+ +----------+
> >
> > The Public SMTP server is MXed as the email host for my.domain. All email
> > from the Internet comes in through this host and is forwarded to the
> > internal SMTP host for delivery. All internal clients use the internal
> > SMTP server for incoming and outgoing email. The internal SMTP server
> > should forward all outgoing email to the Public SMTP server for delivery.
> >
> > I thought I could do this with a transport map on the Public server
> > pointing to the internal SMTP server and vice versa, a transport map on the
> > internal SMTP server pointing to the Public SMTP server. But what I really
> > got was a big mail loop. I seems the transport map looks at both incoming
> > and outgoing email?
> >
> > Any suggestions on how I could do this would be greatly appreciated.
> >
> > Thank you,
> > Matthew Hagerty
> > matthewvenux.net
> >
> >
> >
> >
> >
>
>

------------------------------------------------------------------
  Vladimir Parkhaev, System Administrator, Teleglobe Canada
    vladimirTeleglobe.CA, 514-868-7823(Ph), 514-868-8357(Fax)
       1441 Carrie-Derick, Montreal, Que, Canada H3C 4S9