Currently the Symantec Encryption Management Server does not support IPv6 configuration. 

To see the Feature Request for IPv6 Support for Email Encryption via Symantec Encryption Desktop please visit the following Article: TECH228210

Symantec Corporation is committed to product quality and satisfied customers.  This Feature Request is currently being considered by Symantec Corporation to be addressed in a forthcoming version of the product. 

Technical Support filed a Feature Request to add this product feature. Note that an feature request is exactly that, a request. There is no committed date for this request from the Endpoint Encryption Product Management team, nor from the Endpoint Encryption Engineering team at this time.

Please be sure to refer back to this document periodically as any changes to the status of the request will be reflected here.