Subject: Returned mail: see transcript for details

From: Mail Delivery Subsystem <[email-masked]>
Date: Fri, 27 Jun 2025 13:09:41 GMT

The original message was received at Fri, 27 Jun 2025 13:09:40 GMT
from m0341351.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 [SA2PEPF00001508.namprd04.prod.outlook.com 2025-06-27T13:09:40.874Z 08DDB5403E3CD700])

   ----- Transcript of session follows -----
... while talking to danaher.mail.protection.outlook.com.:
>>> DATA
<<< 550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [SA2PEPF00001508.namprd04.prod.outlook.com 2025-06-27T13:09:40.874Z 08DDB5403E3CD700]
550 5.1.1 <[email-masked]>... User unknown
<<< 503 5.5.2 Need rcpt command [SA2PEPF00001508.namprd04.prod.outlook.com 2025-06-27T13:09:40.874Z 08DDB5403E3CD700]