Subject: Mail delivery failed: returning message to sender

From: Mail Delivery System <[email-masked]>
Date: Thu, 16 Oct 2025 03:09:26 -0700

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

  [email-masked]
    host elu-se.mail.protection.outlook.com [52.101.73.8]
    SMTP error from remote mail server after RCPT TO:<[email-masked]>:
    550 5.4.1 Recipient address rejected: Access denied. For more information see https://aka.ms/EXOSmtpErrors [AM4PEPF00027A67.eurprd04.prod.outlook.com 2025-10-16T10:09:26.904Z 08DE0807D4C86F50]