Subject: Undeliverable: Den mest lönsamma energisparåtgärden är ...

From: <[email-masked]>
Date: Tue, 14 Oct 2025 08:30:09 +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.
[email-masked] only accepts messages from people in its organization or on its allowed senders list, and your email address isn't on the list.
19812_4821_797128_bo. . .       Office 365      johan.frick
Sender          Action Required
Sender not allowed

How to Fix It
It appears you aren't in the same organization as the recipient or your email address isn't on their allowed senders list. Contact the person you're sending your message to (by phone, for example) and tell them to ask their email admin to change the settings on their mailbox so it will accept messages from you.

Was this helpful? Send feedback to Microsoft<https://go.microsoft.com/fwlink/?LinkId=615008>.
________________________________

More Info for Email Admins
Status code: 550 5.7.134

This error occurs when the recipient (an Office 365 mailbox) is configured to accept messages only from authenticated senders (senders in the same organization or those added to the recipient's allowed senders list).

To fix the issue, the recipient's email admin must add the sender's email address to the mailbox's allowed senders list, or they must turn off the mailbox's message delivery restrictions setting that requires that all senders to it are authenticated.

This issue can only be fixed by the recipient's email admin.

For more information and steps to fix this issue, see Fix email delivery issues for error code 5.7.134 in Office 365<https://go.microsoft.com/fwlink/p/?LinkId=615128>.

Original Message Details
Created Date:   10/14/2025 8:30:08 AM
Sender Address: [email-masked]
Recipient Address:      [email-masked]
Subject:        Den mest lönsamma energisparåtgärden är ...

Error Details
Error:  550 5.7.134 RESOLVER.RST.SenderNotAuthenticatedForMailbox; authentication required; Delivery restriction check failed because the sender was not authenticated when sending to this mailbox
Message rejected by:    MM0P280MB0053.SWEP280.PROD.OUTLOOK.COM

Notification Details
Sent by:        MM0P280MB0053.SWEP280.PROD.OUTLOOK.COM

Message Hops
HOP     TIME (UTC)      FROM    TO      WITH    RELAY TIME
1       10/14/2025
8:30:08 AM      [127.0.0.1]     post.nuhet.se   SMTP    *
2       10/14/2025
8:30:08 AM              post.nuhet.se           *
3       10/14/2025
8:30:08 AM      post.nuhet.se   AM3PEPF00009B9E.mail.protection.outlook.com     Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384)   *
4       10/14/2025
8:30:05 AM      AM3PEPF00009B9E.eurprd04.prod.outlook.com       AS4P192CA0001.outlook.office365.com     Microsoft SMTP Server (version=TLS1_3, cipher=TLS_AES_256_GCM_SHA384)   *
5       10/14/2025
8:30:08 AM      AS4P192CA0001.EURP192.PROD.OUTLOOK.COM  MM0P280MB0053.SWEP280.PROD.OUTLOOK.COM  Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384)    3 sec

Original Message Headers

From: Svensk Energiutbildning <[email-masked]>
To: [email-masked]
Reply-To: [email-masked]
Subject: Den mest lönsamma energisparåtgärden är ...
Date: Tue, 14 Oct 2025 10:30:08 +0200

Subject: Den mest lönsamma energisparåtgärden är ...
From: Svensk Energiutbildning <[email-masked]>
To: [email-masked]
Date: Tue, 14 Oct 2025 10:30:08 +0200

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