Re: Client refusing incoming smtp messages

Yes, this is my EXCHANGE server that is causing this SMTP error message.
Another thing, there is not a Cisco Pix involved but there is a Cisco 2600 in
use provided by the ISP. What looks suspicious to me is the modns.moxa.com
domain since I not noticed this before (maybe because all users are working
and never came across this issue before). This problem came to be when I just
created a new user account and sent test messages via the internet because
sometimes smtp errors occur because of typo mistakes and I checked that
already. Maybe should I delete the account and start over? You know glitches
are a part of life these days.... Let me know what's on your minds.
--
Mark Anthony MCSE 2003


"Lanwench [MVP - Exchange]" wrote:

Masitpro_mcse <Masitpromcse@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
What I mean is client using Outlook 2003; sending out internet mai
via SMTP works fine.

OK; let's try this again, because this is important. If you are opening an
Exchange mailbox directly in Outlook (and are not using an Internet mail
account in Outlook), *Outlook* is not sending out Internet mail. Nor is it
receiving it. Instead, your Exchange server is sending and receiving *all*
mail, because it's got your internet domain(s) in its recipient policies,
and your registered internet domain specifies your Exchange server in its MX
records.


But when trying to RECEIVE internet email the
following SMTP error message occurs:

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es)
failed:

PeiJung.Lu@xxxxxxxx
SMTP error from remote mailer after RCPT TO:<PeiJung.Lu@xxxxxxxx>:
host modns.moxa.com [59.124.42.188]: 550 5.1.1
<PeiJung.Lu@xxxxxxxx>... User unknown


This is the NDR message received from the SENDER. The only way the
Outlook client can receive SMTP messages is when I send them thru
telnet. This was how I verified if there is a problem, seems like
SMTP Outlook client only receives internet email via telnet. This is
rather very quirky, so what went wrong?

Again, disregard the client - mentioning it is a bit of a red herring. If
Exchange is handling your mail, the client is not relevant. Is Exchange

The sole MX record for moxa.com is modns.moxa.com (59.124.42.188). If you
are hosting your own mail directly on your Exchange server, that must be
your IP....right?

A telnet to modns.moxa.com on port 25 gives me a

220 ************************************** 200**2****0***00

This looks suspiciously like there's a Cisco Pix in use, as I mentioned
before, and you need to disable MailGuard on it before any further
troubleshooting can be done.

If you do not host your own mail in Exchange (e.g., if that is not your
public IP) then then this is not an Exchange-related issue at all....if
you're using a POP connector, or POP/IMAP anywhere, it's important to
mention that right off the bat.







Masitpro_mcse <Masitpromcse@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
Added new user account to AD/Exchange 2003 and verified smtp
address. Client is able to send out internet email messages

Meaning, using Outlook or OWA to connect directly to the Exchange
mailbox? No Internet Mail service on your mail client, right? .

but will not
accept incoming internet email.

Get following NDR message:

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es)
failed:

client@xxxxxxxxxx
SMTP error from remote mailer after RCPT TO:<client@xxxxxxxxxx>:
host modns.domain.com [59.124.42.188]: 550 5.1.1
<client@xxxxxxxxxx>... User unknown

When I telnet to that IP address on port 25, the banner looks like
you've got a PIX. If so, you need to disable Mailguard on it.

http://support.microsoft.com/kb/295725

This may or may not be the cause of your actual problem - your
description is a bit confusing.


The funny thing is I can send smtp messages via telnet and it is
received at the client mailbox. Always add or modify accounts and I
have not crossed this type of problem before; what to do next?

You'll need to provide more info, I think.

What's your real domain name? No need to hide it - it isn't a state
secret. :)




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