554 5.4.4 SMTPSEND.DNS.NonExistentDomain; nonexistent domain

Question

_{Monday, June 13, 2016 10:29 AM}

Hello,

We have a application on a Linux server that sends out SMTP requests to our Exchange 2010 server, which then should forward it to the relevant recipient.

FYI - Our exchange server is currently in a hybrid state with O365.

We're having trouble with a particular customer, whereby the following NDR is generated

Delivery has failed to these recipients or groups:
rachel@w************nt.co.uk
A problem occurred and this message couldn't be delivered. Check to be sure the e-mail address is correct. If the problem continues, please contact your helpdesk.

Delivery has failed to these recipients or groups:
rachel@w************nt.co.uk
A problem occurred and this message couldn't be delivered. Check to be sure the e-mail address is correct. If the problem continues, please contact your helpdesk.





Diagnostic information for administrators:
Generating server: VEB-S-EXCHANGE.de****.local
rachel@w************t.co.uk
#554 5.4.4 SMTPSEND.DNS.NonExistentDomain; nonexistent domain ##
Original message headers:

Received: from ap.s*********d.com (**7.168.**.230) by

 VEB-S-EXCHANGE.de****.local (192.168.*.*) with Microsoft SMTP Server id

 14.3.266.1; Thu, 2 Jun 2016 15:12:18 +0100

Message-ID: <[email protected]**********d.com>

Date: Thu, 2 Jun 2016 15:12:18 +0100

Subject: Reset Password request

From: Suits Me <hello@s***********d.com>

To: <rachel@wi************ent.co.uk>

MIME-Version: 1.0

Content-Type: text/html; charset="utf-8"

Content-Transfer-Encoding: quoted-printable

Return-Path: hello@s***********d.com

X-EXCLAIMER-MD-CONFIG: 84c02e9f-1293-476d-be63-d27a870a77fb

All replies (3)

_{Tuesday, June 14, 2016 8:55 AM ✅Answered}

From your description, I understand that the particular customer cannot send the message to "<rachel@w************nt.co.uk>" and got the NDR. 

We can found that the error message "554 5.4.4 SMTPSEND.DNS.NonExistentDomain; nonexistent domain" from the NDR. It's means that the issue is about the domain lookup. Please have a test as following:

Send a message from an user (for example: gmail, hotmail) outside our domain to rachel to see if we still receive the same NDR message. 

If yes, please check if the domain "w************nt.co.uk” was configured correctly. Otherwise, we should consider the issue on the sender side. for example: the DNS/MX record settings.

Best regards,

Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact [email protected].

Niko Cheng
TechNet Community Support

_{Tuesday, June 14, 2016 1:38 AM}

What trouble are you having with that particular customer, sending to them or them sending to you?  Do you route outbound mail through Office 365 (EOP)?  Where does your MX record point?

Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."
Celebrating 20 years of providing Exchange peer support!

_{Wednesday, June 22, 2016 7:13 AM}

Hi,

Any updates?

Best regards

Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact [email protected].