Subject: Mail delivery failed: returning message to sender

From: Mail Delivery System <[email-masked]>
Date: Tue, 30 Sep 2025 04:00:35 -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 zaccogroup.mail.protection.outlook.com [52.101.73.6]
    SMTP error from remote mail server after RCPT TO:<[email-masked]>:
    550 5.7.64 TenantAttribution; Relay Access Denied [ValidationStatus of '' is EmptyCertificate] [AMS1EPF00000045.eurprd04.prod.outlook.com 2025-09-30T11:00:35.548Z 08DDFCAC145CFF24]