SOLVED: Re: OT: Setting up a forwarding mail domain in DMZ without pinhole.

Sanjay Arora skpobox at
Mon Aug 23 15:27:22 UTC 2004

On Mon, 2004-08-23 at 17:44, James Wilkinson wrote:
> Peter Boy wrote:
> > The SMTP does not support your model to use your "green" server to
> > "pull" mail from the DMZ server. It is a "push" type communication
> > model.
> Actually, it's little used, but there is support in the protocol. The
> TURN or ETRN command makes the "client" act as the "server", and vice
> versa. So the "green" server would connect to the DMZ server on
> port 25 (an outbound connection), issue ETRN, and then the DMZ would
> push any mail it had queued to the "green" server.
> Obviously, both servers have to support this. And no, I've never used
> qmail, so I don't know if or how it would do this.

Thanks James

you solved my problem. It is available in qmail with a patch called

For anyone looking for a similar solution, I quote below from qmail faq

Best regards and thanks to all the people on the list for helping me.


> How do I send messages by SMTP to an authorized dialup host when it
> makes an SMTP connection? I've heard about ETRN and AutoTURN. 
> Answer: This answer assumes that you are running qmail-smtpd under
> tcpserver.
> Install serialmail and read /usr/local/doc/serialmail/AUTOTURN.
> AutoTURN works with clients that send ETRN. It also works with clients
> that don't send ETRN.

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