To enable the De-Mail integration:
In the GroupWise Admin console, select the Domain, Post Office, or user where you want the De-Mail integration enabled.
Go to Client Options > Integrations > DE Mail and select Enable DE Mail integration.
Select if you want to Use Mentana filtering or Use TSystem filtering.
With this enabled, users who send items to a De-Mail address are able to select additional De-Mail security options in the item header previous to sending the item.