Just #< #5.0.0> #SMTP#

Question

I have a smart host in a MS server (remote.X.pt) with Exchange 2007, that is connected to a remote mail server (cpanel.ideiasfrescas.pt) and it is working fine. Right now i am unable to send some mails for certain email destinations, it seems that my remote mail server is not letting go those mails dont know well, with a Undeliverable message:

An error occurred while trying to deliver this message to the recipient's e-mail address. Microsoft Exchange will not try to redeliver this message for you. Please try resending this message, or provide the following diagnostic text to your system administrator.

Diagnostic information for administrators:

Generating server: cpanel.ideiasfrescas.pt

#< #5.0.0> #SMTP#

Original message headers:

Return-Path: <[email protected]>
Received: from 195-23-X-174.static.net.novis.pt ([]:52706 helo=remote.X.pt)
        by cpanel.ideiasfrescas.pt with esmtpsa (TLSv1:AES128-SHA:128)
        (Exim 4.87)
        (envelope-from <[email protected]>)
        id 1cEaph-002kde-L9
        for <destination email>; Wed, 07 Dec 2016 11:56:22 +0000
Received: from X.gfe-sa.local ([fe80::2a2:e713:56d1:905a]) by
 X.gfe-sa.local ([fe80::2a2:e713:56d1:905a%18]) with mapi; Wed, 7 Dec
 2016 11:56:20 +0000
From: <[email protected]>
To:  <destination email>
CC:  <[email protected]>, Sales <[email protected]>
Date: Wed, 7 Dec 2016 11:56:21 +0000
Subject: RE: Rush Order
Thread-Topic: Rush Order
Thread-Index: AdJQTgn1c02dWI2hRkqBELMYBWQ9VAAMnFIA
Message-ID: <[email protected]>
References: <007801d2504e$0df532d0$29df9870$@com>
In-Reply-To: <007801d2504e$0df532d0$29df9870$@com>
Accept-Language: en-US, pt-PT
Content-Language: pt-PT
X-MS-Has-Attach: yes
X-MS-TNEF-Correlator:
acceptlanguage: en-US, pt-PT
Content-Type: text/plain
MIME-Version: 1.0
X-Exim-DSN-Information: Due to administrative limits only headers are returned

Searching about this SMTP error i have found that:

SMTP 500 reply code means an unrecognised command. You get this NDR when you make a typing mistake when you manually try to send email via telnet. More likely, a routing group error, no routing connector, or no suitable address space in the connector. (Try adding * in the address space) This status code is a general error message in Exchange 2000. In fact Microsoft introduced a service pack to make sure now get a more specific code.

But i cannot relate with this problem, since this is not a new user in the system, it was working fine till now.

I am able to send mails to outside domains through my remote mail server.

If you need more info or data just ask.

Anyone knows what is happening?

Solution

Vendors do not stick to the SMTP error codes completely, so getting a 5.5.0 without any additional message is not going to help with diagnostics.

If you sending via this server as a smart host, the first thing I would do is a telnet test from the Exchange server to the remote server to see whether that shows any issue.

The most likely cause is external interference. AV scanning something it shouldn't be, firewall scanning SMTP traffic, something like that.

Comments

[marafado88]

Thanks Sembee, after a while i notice that this problem was from my remote server, and not from my smart host.