Subject: Undelivered Mail Returned to Sender

From: [email-masked] (Mail Delivery System)
Date: Thu, 15 Jan 2026 13:33:09 +0000 (UTC)

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<[email-masked]>: host
    kaufmann-cl.mail.protection.outlook.com[52.101.8.51] said: 550 5.4.1
    Recipient address rejected: Access denied. For more information see
    https://aka.ms/EXOSmtpErrors [DS3PEPF0000C37B.namprd04.prod.outlook.com
    2026-01-15T13:33:09.651Z 08DE53F4E5979141] (in reply to RCPT TO command)