Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Mon, 14 Jul 2025 13:01:14 GMT

The original message was received at Mon, 14 Jul 2025 13:01:13 GMT
from m0424592.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 [DU6PEPF0000B622.eurprd02.prod.outlook.com 2025-07-14T13:01:14.302Z 08DDBF133CA51EB5])

   ----- Transcript of session follows -----
... while talking to sgrailing-no.mail.protection.outlook.com.:
>>> DATA
<<< 550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [DU6PEPF0000B622.eurprd02.prod.outlook.com 2025-07-14T13:01:14.302Z 08DDBF133CA51EB5]
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.5.2 Need rcpt command [DU6PEPF0000B622.eurprd02.prod.outlook.com 2025-07-14T13:01:14.302Z 08DDBF133CA51EB5]