Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Mon, 20 Oct 2025 14:56:48 +0200

The original message was received at Mon, 20 Oct 2025 14:56:47 +0200
from m0417415.ppops.net [127.0.0.1]

   ----- The following addresses had permanent fatal errors -----
<[email-masked]>
    (reason: 550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [DB3PEPF0000885A.eurprd02.prod.outlook.com 2025-10-20T12:56:48.024Z 08DE0D5DEB689F7F])

   ----- Transcript of session follows -----
... while talking to brenntagnordic-com02b.mail.protection.outlook.com.:
>>> DATA
<<< 550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [DB3PEPF0000885A.eurprd02.prod.outlook.com 2025-10-20T12:56:48.024Z 08DE0D5DEB689F7F]
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.5.2 Need rcpt command [DB3PEPF0000885A.eurprd02.prod.outlook.com 2025-10-20T12:56:48.024Z 08DE0D5DEB689F7F]