Gmail Messages Bouncing:  Exchange 2007-  550 mailbox unavailable (state 18)

Posted on 2011-09-19
Last Modified: 2012-05-12
Microsoft Exchange 2007 SP1
Watchguard Firewall
TrendMicro Worry Free Advanced (Spam Filtering)
HughesNet Satellite ISP

Problem:  Messages sent from Gmail, etc are receving:

Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 Requested action not taken: mailbox unavailable (state 18).

Exchange sends fine , and receives some mail correctly (nothing in the Que - Watchguard routing correctly)
MXToolbox shows MX record correctly knows hostname
MXToolbox shows no blacklist issues shows everything working correctly.
Nothing in the Trend Quarantine or logs
Hughesnet has indicated that it will NOT create a PTR record for my static IP.

Seems as though the message is getting rejected early in the process...

A. What is the problem?
B. How can I remedy this?

Question by:NorthernHills
  • 5
  • 2
LVL 14

Expert Comment

ID: 36562919
You should enable logging on the firewall and see if that is blocking the mail.
Otherwise you could try and setup an exception in WG smtp proxy for *
and the same for the Trend Micro, and see if it helps.
LVL 20

Assisted Solution

by:Satya Pathak
Satya Pathak earned 50 total points
ID: 36563216
Please go through .. i think below mentioned article will be help you .. 


Author Comment

ID: 36563233
Im not using spamblocker on Watchguard (nor antivirus), and do not get a watchguard error.  The returned email is as follows:

Received: by with SMTP id e32cs348094yhg;
        Mon, 19 Sep 2011 13:20:19 -0700 (PDT)
Received: from ([])
        by with SMTP id y22mr24567691yhl.103.1316463619276 (num_hops = 1);
        Mon, 19 Sep 2011 13:20:19 -0700 (PDT)
Received: by with SMTP id y22mr16730537yhl.103.1316463619171;
        Mon, 19 Sep 2011 13:20:19 -0700 (PDT)
MIME-Version: 1.0
Return-Path: <>
Received: by with SMTP id y22mr24564901yhl.103; Mon, 19 Sep 2011
 13:20:19 -0700 (PDT)
From: Mail Delivery Subsystem <>
Subject: Delivery Status Notification (Failure)
Message-ID: <>
Date: Mon, 19 Sep 2011 20:20:19 +0000
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

Delivery to the following recipient failed permanently:

Technical details of permanent failure:=20
Google tried to deliver your message, but it was rejected by the recipient =
domain. We recommend contacting the other email provider for further inform=
ation about the cause of this error. The error that the other server return=
ed was: 550 550 Requested action not taken: mailbox unavailable (state 18).

----- Original message -----

MIME-Version: 1.0
Received: by with SMTP id y22mr16728612yhl.103.1316463602788;
 Mon, 19 Sep 2011 13:20:02 -0700 (PDT)
Received: by with HTTP; Mon, 19 Sep 2011 13:20:02 -0700 (PDT)
Date: Mon, 19 Sep 2011 14:20:02 -0600
Message-ID: <
Subject: Testing 10
From: ThatsMe <>
Content-Type: multipart/alternative; boundary=3D20cf305e287f6768b104ad51111=


Author Comment

ID: 36563275
Just saw something...

My A records:
@ = (web server ) working!
mail =
remote =
smtp =

ftp= @
www  @


10 - @ - (this is the same on the outbound and incoming connectors on exchange 2007)

Question is, do I need to use MAIL - instead of "remote"

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Author Comment

ID: 36563333
Restarted all spam filtering on server in exchange - still no joy
LVL 14

Accepted Solution

setasoujiro earned 450 total points
ID: 36564921
No you do not need to use mail instead of remote.

Can you use telnet to deliver a mail to your site with a gmail address?
just in case you don't know how to to this: download PUTTY

telnet into your mailserver from external :
telnet "" on port 25
ehlo (or helo, depends on the server)
mail from:
rcpt to:
subject: test



don't fortget the " . " at the end to close


Assisted Solution

NorthernHills earned 0 total points
ID: 36588751
So turns out it was a couple issues...

Had to remove the xxx.local as the default mail handler, and replace with

Didnt work immediately, but by the next morning was taking in email correctly.

Points split!

Author Closing Comment

ID: 36715382
All answers contributed to us finding the solution!

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