Your Users send encrypted emails using Symantec Policy Based Encryption-Z (PBE-Z). Shortly after the user receives a non delivery receipt (NDR) or bounced email stating delivery failed to the intended recipient.
Delivery has failed to these recipients or groups:
A problem occurred during the delivery of this message. Please try to resend the message later. If the problem continues, contact your helpdesk.
Diagnostic information for administrators:
Generating server: server-**.bemta-**.messagelabs.com
Remote Server returned '< #5.4.6 smtp; 551 5.4.6 [internal] Private/Loopback Address>'
The inbound route configured for the registered subdomain for the PBE-Z service has been incorrectly configured. When subscribed to the PBE-Z service, 2 subdomains will be added to your account.
encryptz-**.yourdomain.com (where ** is either US or EU depending on your region and yourdomain.com replaced by your organization's domain)
Each of these subdomains will be configured with a custom inbound route unique to them. This is to ensure, once the email triggers your encryption policy, that it is routed to the proper encryption server and processed for delivery. these routes will be the following, depending on your region.