Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Tue, 13 Jan 2026 08:03:52 +0100

The original message was received at Tue, 13 Jan 2026 08:03:51 +0100
from m0220690.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 [DU2PEPF00028CFD.eurprd03.prod.outlook.com 2026-01-13T07:03:52.310Z 08DE4E6920A458C2])

   ----- Transcript of session follows -----
... while talking to storebrand.mail.protection.outlook.com.:
>>> DATA
<<< 550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [DU2PEPF00028CFD.eurprd03.prod.outlook.com 2026-01-13T07:03:52.310Z 08DE4E6920A458C2]
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.5.2 Need rcpt command [DU2PEPF00028CFD.eurprd03.prod.outlook.com 2026-01-13T07:03:52.310Z 08DE4E6920A458C2]