Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Fri, 29 Aug 2025 17:37:42 +0200

The original message was received at Fri, 29 Aug 2025 17:37:42 +0200
from m0417413.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 [AMS0EPF000001A2.eurprd05.prod.outlook.com 2025-08-29T15:37:42.472Z 08DDE70FF6BF5578])

   ----- 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 [AMS0EPF000001A2.eurprd05.prod.outlook.com 2025-08-29T15:37:42.472Z 08DDE70FF6BF5578]
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.5.2 Need rcpt command [AMS0EPF000001A2.eurprd05.prod.outlook.com 2025-08-29T15:37:42.472Z 08DDE70FF6BF5578]