Client of mine tried to send an email to someone and got this bounce back. I am able to send emails from a different domain to this person. NDR is below.

Delivery has failed to these recipients or distribution lists:

email2 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.

The following organization rejected your message: Requested.

Sent by Microsoft Exchange Server 2007

Diagnostic information for administrators:

Generating server: local

email2 Requested #550 Requested action not taken: mailbox unavailable ##

Original message headers:

Received: from local ([IP]) by

 local ([IP]) with mapi; Mon, 4 May 2015

 16:15:12 -0300

From: email1 <email1>

To: "email2" <email2>

Date: Mon, 4 May 2015 16:15:11 -0300

Subject: Test

Thread-Topic: Test

Thread-Index: AdCGnqG7Z0yHeIW7TOiKidfR/nR4cw==

Message-ID: <ID@Local>

Accept-Language: en-US

Content-Language: en-US

X-MS-Has-Attach: yes

X-MS-TNEF-Correlator:

acceptlanguage: en-US

x-tm-as-product-ver: SMEX-10.1.0.1137-6.800.1017-18790.000

x-tm-as-result: Yes-11.878200-5.000000-31

x-tm-as-user-approved-sender: No

x-tm-as-user-blocked-sender: No

Content-Type: multipart/related;

        boundary="_007_B7C5B627E87C9244879ACEC3CDC584922EF6EB52B6KEIZERSERVERk_";

        type="multipart/alternative"

MIME-Version: 1.0

• Edited by JDrew85 Tuesday, May 05, 2015 4:22 PM sensitive info

Hi,

I would like to verify if you can send emails to other external domains. What's more, please check if this problematic domain block your domain emails.

Hope this can be helpful to you.

Best regards,

Check to see if the domain the user is sending from is blacklisted anywhere, you can do that by using mxtoolbox, http://mxtoolbox.com/SuperTool.aspx

Also, check to see if it is every person at your client, or just a specific person or people, that should help narrow this down quite a bit.

MXToolbox has a handy tool for dissecting message headers:

http://mxtoolbox.com/EmailHeaders.aspxs.aspx

Also.. if the "Requested #550 Requested action not taken: mailbox unavailable ##"  This is typically a message from the receiving mail server.  Which could mean the email address is mistyped, the mailbox on the recipient server is full, or offline, etc.  try using the header analyzer on both the message that is rejected, and the message from the other domain that is accepted.

• Edited by JoeFri 18 hours 24 minutes ago