Len-
Few questions.
When you say 'behind NAT', can you be more specific? Is it a firewall,
proxy, router-based NAT?
Before that is even answered, let's make sure you are trying to do the right
thing. If your customer is connected to you via leased line, you should
never even NEED ETRN. ETRN is designed for sites who are not continously
connected to the Internet. Even if the line goes down momentarily, provided
that you have the correct DNS and HOSTS entries for your customer's domain,
IMAIL will properly hold the mail and retry the mail on it's own, WITHOUT
receiving an ETRN request. ETRN is especially important for dialup customers
because the chances of IMAIL trying to de-spool waiting mail at the SAME
EXACT time your dialup user's Exchange server is connected to you is remote.
Hence ETRN allows Exchange to signal IMAIL and let it know that's it is now
online and ready to receive any waiting mail.
You said that Exchange is using SMTP to forward outbound mail to you, and
IMAIL is sending all inbound mail to the trusted NAT IP. So if it's a leased
line (by that, I assume you mean some sort of dedicated connection that is
not dialup), then when does IMAIL even have mail for this domain sitting in
queue? Perhaps if the line drops, as I said, or your customer reboots the
Exchange server. In those cases, just have IMAIL configured to spool the
mail, and it will retry sending the mail to your customer on it's own
without receiving an ETRN command.
If NAT is the issue here, and I'm mis-reading your question, then your
answer to my first question will help determine what you need to do to solve
this problem....
Scot Desort
NJ Internet Access
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Len Conrad
> Sent: Monday, August 23, 1999 10:19 AM
> To: [EMAIL PROTECTED]
> Subject: [IMail Forum] ERTN by Exchange over leased line?
>
>
> Our client connects to us via a leased line. He has Exchange behind NAT,
> so Imail forwarding can't reach it by MX connection.
>
> We'd like his Exhange to us ESTMP and ETRN to come pick up the mail. We
> can't see how to configure Exchange to this. Over dialup lines, yes, but
> over a
> leased line, no.
>
> Exchange forwards mail to our Imail just fine. Imail accepts it as being
> from a trusted ip address and relays it on.
>
> Imail is receiving and spooling mail from Internet for the
> client's domain
> and trying to forward it to the trusted ip address (outside ip on his NAT
> box). cool
>
> The pb is Exchange is not ETRNing to pick up its waiting mail.
>
> Suggestions?
>
> Len
>
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