Subject: Undeliverable: Kurs om hur man driftoptimerar och energieffektiviserar byggnaders installationssystem

From: <[email-masked]>
Date: Mon, 15 Sep 2025 05:02:00 +0000

[https://products.office.com/en-us/CMSImages/Office365Logo_Orange.png?version=b8d100a9-0a8b-8e6a-88e1-ef488fee0470]
Your message to [email-masked] couldn't be delivered.
ronnie.chressman wasn't found at regionstockholm.se, or the mailbox is unavailable.
19812_4779_722079_bo. . .       Office 365      ronnie.chressman
Action Required                 Recipient
Unknown To address

How to Fix It
The email address might be misspelled or it might not exist. Try one or more of the following:

  *   Retype the recipient's address, then resend the message - If you're using Outlook, open this non-delivery report message and click Send Again from the menu or ribbon. In Outlook on the web, select this message, and then click the "To send this message again, click here." link located just above the message preview window. In the To or Cc line, delete and then retype the entire recipient's address (ignore any address suggestions). After typing the complete address, click Send to resend the message. If you're using an email program other than Outlook or Outlook on the web, follow its standard way for resending a message. Just be sure to delete and retype the recipient's entire address before resending it.
  *   Remove the recipient from the recipient Auto-Complete List, then resend the message - If you're using Outlook or Outlook on the web, follow the steps in the "Remove the recipient from the recipient Auto-Complete List" section of this article<https://go.microsoft.com/fwlink/?LinkId=532972>. Then resend the message. Be sure to delete and retype the recipient's entire address before clicking Send.
  *   Contact the recipient by some other means, (by phone, for example) to confirm you're using the right address. Ask them if they've set up an email forwarding rule that could be forwarding your message to an incorrect address.

If the problem continues, forward this message to your email admin. If you're an email admin, refer to the More Info for Email Admins section below.

Was this helpful? Send feedback to Microsoft<https://go.microsoft.com/fwlink/p/?LinkID=717200>.
________________________________

More Info for Email Admins
Status code: 550 5.1.351

When Office 365 tried to send the message, the external email server returned an error stating that the recipient is unknown or the mailbox is unavailable. This error was reported by an email server outside Office 365.

If you or the sender can't fix the problem, contact the responsible party's email admin - Give them the error code and error message from this non-delivery report (NDR) to help them troubleshoot the issue. To determine who the responsible party might be, check the error for information about where the problem is happening. For example, look for a domain name like contoso.com. A domain name in the error might suggest who is responsible for the error. It could be the recipient's email server, or it could be a third-party service that your organization or the recipient's organization is using to process or filter email messages.

Although the sender might be able to fix the issue by correcting the recipient address, it's likely that only the recipient's email admin can fix the problem. Unfortunately, it's unlikely Office 365 Support will be able to help with these kinds of externally reported errors.

Original Message Details
Created Date:   9/15/2025 5:00:12 AM
Sender Address: [email-masked]
Recipient Address:      [email-masked]
Subject:        Kurs om hur man driftoptimerar och energieffektiviserar byggnaders installationssystem

Error Details
Error:  550 5.1.351 Remote server returned unknown recipient or mailbox unavailable -> 550 [email-masked]... No such user
Message rejected by:    smtp02.sll.se

Notification Details
Sent by:        GV3P280MB0339.SWEP280.PROD.OUTLOOK.COM

Message Hops
HOP     TIME (UTC)      FROM    TO      WITH    RELAY TIME
1       9/15/2025
5:00:12 AM      [127.0.0.1]     post.nuhet.se   SMTP    *
2       9/15/2025
5:00:12 AM              post.nuhet.se           *
3       9/15/2025
5:00:19 AM      post.nuhet.se   in43f.electric.net      esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98) (envelope-from <[email-masked]>)  7 sec
4       9/15/2025
5:00:20 AM              emcmailer               1 sec
5       9/15/2025
5:00:20 AM      1uy1K7-000000005ow-2h4l in43f.electric.net      hostsite:2502457 (Exim 4.98) (envelope-from <[email-masked]>)   *
6       9/15/2025
5:00:21 AM      smtp-in43.electric.net  AM3PEPF00009B9C.mail.protection.outlook.com     Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384)    1 sec
7       9/15/2025
5:00:17 AM      AM3PEPF00009B9C.eurprd04.prod.outlook.com       AS8PR07CA0037.outlook.office365.com     Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384)   *
8       9/15/2025
5:00:21 AM      AS8PR07CA0037.eurprd07.prod.outlook.com GV3P280MB0339.SWEP280.PROD.OUTLOOK.COM  Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384)    4 sec

Original Message Headers

Authentication-Results-Original: in43f.electric.net;    iprev=pass
 (post.nuhet.se) smtp.remote-ip=85.118.203.81;  spf=pass
 smtp.mailfrom=post.nuhet.se;   dmarc=skipped
From: Svensk Energiutbildning <[email-masked]>
To: [email-masked]
Reply-To: [email-masked]
Subject: Kurs om hur man driftoptimerar och energieffektiviserar byggnaders
 installationssystem
Date: Mon, 15 Sep 2025 07:00:12 +0200
X-Authenticated_ID:
 =?us-ascii?Q?pDAuv2rsCW7mi7GGb/kb/Qq9U3w+q8BmseTE8v9uTc133vw+Vc/uLAnvqK/3?=
 =?us-ascii?Q?sl19s/UgYRm7rYez32Ql+NjCKg=3D=3D?=
X-Forefront-Antispam-Report:
        CIP:208.70.135.36;CTRY:US;LANG:sv;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:smtp-in43.electric.net;PTR:smtp-in43.electric.net;CAT:NONE;SFS:(13230040)(34020700016)(4022899009)(3072899012)(2092899012)(39142699007)(31052699007)(82310400026)(69100299015)(12012899012)(4076899003)(8096899003)(13003099007);DIR:INB;
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-ChunkCount: 1
X-MS-Exchange-AntiSpam-ExternalHop-MessageData-0:
        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
X-OriginatorOrg: sllse.onmicrosoft.com
X-MS-Exchange-CrossTenant-OriginalArrivalTime: 15 Sep 2025 05:00:21.4816
 (UTC)
X-MS-Exchange-CrossTenant-Network-Message-Id: 08e1c198-dfb2-4f4a-5469-08ddf414c5ff
X-MS-Exchange-CrossTenant-Id: 73c667fd-62b7-4783-8cbf-cf2f2e3a3067
X-MS-Exchange-CrossTenant-AuthSource:
        AM3PEPF00009B9C.eurprd04.prod.outlook.com
X-MS-Exchange-CrossTenant-AuthAs: Anonymous
X-MS-Exchange-CrossTenant-FromEntityHeader: Internet
X-MS-Exchange-Transport-CrossTenantHeadersStamped: GV3P280MB0339
X-OrganizationHeadersPreserved: GV3P280MB0339.SWEP280.PROD.OUTLOOK.COM
X-CrossPremisesHeadersFilteredByDsnGenerator:
        GV3P280MB0339.SWEP280.PROD.OUTLOOK.COM

Subject: Kurs om hur man driftoptimerar och energieffektiviserar byggnaders installationssystem
From: Svensk Energiutbildning <[email-masked]>
To: [email-masked]
Date: Mon, 15 Sep 2025 07:00:12 +0200

Installationsteknisk energieffektiviseringKurs om hur man driftoptimerar och energieffektiviserar byggnader 
med installationstekniska åtgärder.