Messages are delivered to Symantec Messaging Gateway (SMG) Content Encryption service as expected but replies are not received.
I can send mail with Content Encryption, but I do not get replies back.
Mesaging Gateway is most likely not configured to offer TLS for inbound SMTP connections.
The encryption service provider requires that replies to Content Encryption secured messages be delivered with TLS encryption but Messaging Gateway has not be configued to offer TLS encryption for inbound mail.
This issue may be addressed by configuring Messaging Gateway to offer TLS encryption for Inbound mail traffic.