This article describes how PGP Universal Server can manage external user keys.
There are a number of options on the PGP Universal Server that you can use for management of external user PGP keys.
External UsersExternal users can run PGP Universal Satellite or PGP Desktop, or they can interact with the PGP Universal Server through PGP Universal Web Messenger.
Verified DirectoryThe PGP Verified Directory gives you the option of hosting a Web-accessible keyserver for the public keys of your internal or external users. By enabling the Verified Directory feature on the PGP Universal Server you can allow external users to upload their keys to your server.
KeyserverIf you know of a keyserver or directory outside your own network that can contain keys belonging to people receiving mail from inside your network, you can add that keyserver to the list of searchable keyservers. The PGP Universal Server searches the specified keyserver for recipient keys or certificates, if mail policy rules containing that keyserver apply to the message being sent.