Email Moderation Error

Question

Hi,
I am having this issue as a moderator. when someone wants to send a message to a certain group in my company, the email comes to me first, i then decide whether to approve the message or not. when i click on accept i receive the following error;
DB3FFO11FD001.mail.protection.outlook.com rejected your message to the following email addresses:
Microsoft Exchange (SystemMailbox{bb558c35-97f1-4cb9-8ff7-xxxxxxxxx}@xxxxxx.onmicrosoft.com)
DB3FFO11FD001.mail.protection.outlook.com gave this error: [SystemMailbox{bb558c35-97f1-4cb9-8ff7-xxxxxxxxx}@xxxxxxx.onmicrosoft.com]: Recipient address rejected: Access denied
A communication failure occurred during the delivery of this message. Please try resending the message later. If the problem continues, contact your helpdesk.
Diagnostic information for administrators:
Generating server: xxxx.co.ke
SystemMailbox{bb558c35-97f1-4cb9-8ff7-xxxxxx}@xxxxx.onmicrosoft.com
DB3FFO11FD001.mail.protection.outlook.com Remote Server returned '550 5.4.1 [SystemMailbox{bb558c35-97f1-4cb9-8ff7-xxxxxxxxx}@xxxxx.onmicrosoft.com]: Recipient address rejected: Access denied'
Original message headers:
Received: from xxxxx.co.ke (192.168.xx.xx) by xxxx.co.ke (192.168.xx.xx) with Microsoft SMTP Server (TLS) id
15.0.847.32; Wed, 26 Nov 2014 10:49:55 +0300
Received: from xxxx.co.ke ([fe80::4b9:1080:7301:f8be]) by
xxxx.co.ke ([fe80::4b9:1080:7301:f8be%13]) with mapi id
15.00.0847.030; Wed, 26 Nov 2014 10:49:54 +0300
From: "xxxx xxxxx" <[email protected]>
To: Microsoft Exchange
        <SystemMailbox{bb558c35-97f1-4cb9-8ff7-xxxxxx}@xxxxxx.onmicrosoft.com>
Subject: Approve: Fixed Asset Stock Take
Thread-Topic: Fixed Asset Stock Take
Thread-Index: AdAJQBLkWpL1pl2ZTvqlQ8qnRPeE+AAA5IIgAAACAV0AAnjdQA==
Date: Wed, 26 Nov 2014 07:49:53 +0000
Message-ID: <[email protected]>
Accept-Language: en-US
Content-Language: en-US
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
x-originating-ip: [192.168.100.91]
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
What is the likely possibility of this error to occur? Is it bcoz the user sending the email is from cloud, and i am on premise that is y i cant approve the email?
Regards. 
Khuzema R.
Kind Regards, Khuzema R.

Answer 1

Hi Rashid,
According to my research and test, NDR will deliver to sender instead of arbitration mailbox. More details about
Manage message approval, for you reference:
http://technet.microsoft.com/en-us/library/dd297936(v=exchg.150).aspx
From error message ‘DB3FFO11FD001.mail.protection.outlook.com rejected your message to the following email addresses…’, I want to double confirm whether this mail delivery is within an organization.
I find a similar thread about this error, please refer to:
https://social.technet.microsoft.com/Forums/exchange/en-US/c24e7102-a68c-442d-b267-0a1038dddaa0/my-mail-are-getting-rejected-from-outside-servers
Best regard,
Allen Wang