Troubleshooting Symantec Network Prevent integration: deferred messages
If outbound email returns with the following error:
421 Forwarding agent unavailable. Closing connection.
the Remote SMTP Listener Port for Symantec Network Prevent does not match the inbound email port on Symantec Brightmail Gateway.
See Configuring Symantec Network Prevent to return email to Symantec Brightmail Gateway.
This message describes the error that is seen in Symantec Data Loss Prevention from Symantec Version 8.1. Future versions may produce different errors.