In order to create, send, retrieve, or process packages, the User Groups assigned to Document Transfer packages require the Document Transfer Administrative Processing Privilege (under Product Rights).
Note:
A user who is not a member of a User Group with the Document Transfer product right can still stage a package using the Create Transfer Package right-click option from an Envelope if that user has full control permissions for the Envelope and if that Envelope is assigned to a package.
For complete details on configuring User Groups, see the System Administration module reference guide.