Azure AD exchange outbound email to any known good .edu domain bouncing back as undeliverable.

Question

Azure AD exchange outbound email to any known good .edu domain bouncing back as undeliverable.

Myles Michael 0

Emails sent from our domain to any .edu domain addresses are bouncing back as undeliverable.

Tested with several different .edu domains and all bounce back as undeliverable. Tested to a known good students email account and same thing.

Andy David - MVP 158K Reputation points MVP Volunteer Moderator

2023-05-19T17:09:25.6866667+00:00

what is the exact NDR? (minus any personal info)

Myles Michael 0

Diagnostic information for administrators:
Generating server: XXXXXXXXXX.XXXXXX.edu
******@xxxx.xxxx.edu
Remote Server returned '550 5.1.10 RESOLVER.ADR.RecipientNotFound; Recipient not found by SMTP address lookup'
Original message headers:
Received: from XXXXXXXXXX.XXXXXX.edu (xxx.xxx.xxx.xxx) by
 XXXXXXXXXX.XXXXXX.edu (xxx.xxx.xxx.xxx) with Microsoft SMTP Server
 (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id
 15.1.2375.34; Fri, 19 May 2023 10:39:08 -0600
Received: from XXXXXXXXXX.XXXXXX.edu (xxx.xxx.xxx.xxx) by
 XXXXXXXXXX.XXXXXX.edu (xxx.xxx.xxx.xxx) with Microsoft SMTP Server
 (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id
 15.1.2375.34 via Frontend Transport; Fri, 19 May 2023 10:39:08 -0600
Authentication-Results: XXXXXXXXXX.XXXXXX.edu; dkim=none (message not signed) header.i=none; spf=Pass smtp.mailfrom=******@xxxxxxx.com; spf=Pass smtp.helo=******@NAM12-DM6-obe.outbound.protection.outlook.com
Received-SPF: Pass (XXXXXXXXXX.XXXXXX.edu: domain of
  ******@xxxxxx.com designates xxx.xxx.xxx.xxx as permitted
  sender) identity=mailfrom; client-ip=xxx.xxx.xxx.xxx;
  receiver= XXXXXXXXXX.XXXXXX.edu;
  envelope-from="******@xxxx.com";
  x-sender="******@xxxx.com"; x-conformance=spf_only;
  x-record-type="v=spf1"; x-record-text="v=spf1
  ip4:40.92.0.0/15 ip4:40.107.0.0/16 ip4:52.100.0.0/14
  ip4:104.47.0.0/17 ip6:2a01:111:f400::/48
  ip6:2a01:111:f403::/49 ip6:2a01:111:f403:8000::/50
  ip6:2a01:111:f403:c000::/51 ip6:2a01:111:f403:f000::/52 -all"
Received-SPF: Pass (xxxxx.edu: domain of
  ******@NAM12-DM6-obe.outbound.protection.outlook.com
  designates 40.107.243.99 as permitted sender) identity=helo;
  client-ip=40.107.243.99; receiver=xxxxx.edu;
  envelope-from="******@xxxx.com";
  x-sender="******@NAM12-DM6-obe.outbound.protection.outlook.com";
  x-conformance=spf_only; x-record-type="v=spf1";
  x-record-text="v=spf1 ip4:40.92.0.0/15 ip4:40.107.0.0/16
  ip4:52.100.0.0/14 ip4:104.47.0.0/17 ip6:2a01:111:f400::/48
  ip6:2a01:111:f403::/49 ip6:2a01:111:f403:8000::/50
  ip6:2a01:111:f403:c000::/51 ip6:2a01:111:f403:f000::/52 -all"
X-Ironport-Dmarc-Check-Result: validskip
IronPort-SDR: kJgaE+LPVZ7S9AexW+t217sLTI3L8JfpDu055ctuWYmncv7XfgFrW3QAsaEStmeHlx0cp5rv7y
 9PSV5tv8cbKTdkiiZ1mpgCfHtPmtCLQD/v00wftR7xGyTKkEtCFLe9O48GgLEyNio1BoJlVO6O
 K4wANGfgAtB/4TMadD0cjTAnw4Gruxz6uNxjR02PXPpPE5PKElhpHY7dyu2GLu8baLbyztaBgx
 +j6lMFh1dsoA3lbT6bM36+7wf15/2EPEuMq1zhazV798/enwOk7aNhKIaWOdcEDfSUE1+FLzTQ
 NnHK5wxo2BB4mWoru+tcJLzb
X-AttachmentName: image001.jpg
X-Reputation: 3.5

I think this is what your asking for? Sent this to my son's college email account from our Azure AD hosted domain with Microsoft. Other coworkers getting same errors to other .edu domains.

Aholic Liang-MSFT 13,891 Reputation points Microsoft External Staff

2023-05-29T09:59:40.6033333+00:00

Hi @ Myles Michael,

Just checking in to see how things are going on with this thread.

If the reply was helpful, you can click the "Accept Answer" button under this post so that other's with similar question can benefit from this thread as well.

If you still have further questions or concerns, feel free to post back.

1 answer

Your answer

Andy David - MVP 158K Reputation points MVP Volunteer Moderator

2023-05-19T17:09:25.6866667+00:00

what is the exact NDR? (minus any personal info)
Aholic Liang-MSFT 13,891 Reputation points Microsoft External Staff

2023-05-29T09:59:40.6033333+00:00

Hi @ Myles Michael,

Just checking in to see how things are going on with this thread.

If the reply was helpful, you can click the "Accept Answer" button under this post so that other's with similar question can benefit from this thread as well.

If you still have further questions or concerns, feel free to post back.

Answer 1

Hi @ Myles Michael,

In order to better confirm the issue, I would like to confirm the following points with you:

1. Are you receiving NDR for messages sent in Outlook client? Does the error persist in sending mail from OWA?

2. Please verify that the recipient's address in NDR is the same as the original email?

3. Try removing the recipient from the AutoComplete drop-down list, retyping the full and correct recipient email address, and sending to see if anything changes.

4. Can you send mail to a different domain successfully?

If only one recipient in one domain cannot send, I recommend that you contact the recipient or the administrator of this organization to check for any forwarding or redirection rules.

In addition, I also found this troubleshooting guide about this error：Fix NDR error 550 5.1.10 in Exchange Online - Exchange | Microsoft Learn

Hope the above is helpful to you！

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Aholic Liang-MSFT 13,891 Reputation points Microsoft External Staff

2023-05-24T10:00:52.3866667+00:00

Hi @ Myles Michael,

I am writing here to confirm with you how thing going now?

Please let us know if you would like further assistance.

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Azure AD exchange outbound email to any known good .edu domain bouncing back as undeliverable.

1 answer

Your answer