Not getting many responses, so I'm thinking I should rephrase my question or provide more information.
My impression of using this tool is only under very planned circumstances. The server has to have access to your public key to encrypt any information that it sends to you. So it seems like you have to configure it yourself, in other words, it has to be your server.
And as far as using this type of encryption with e-mail, is this only used when you have made agreements with others in advance? So, if I want to send encrypted e-mails to my friend Jack, I have to send him my public key first, and then he has to add it to his public keyring. Only then will we be able to send encrypted e-mails to each other.
So, again, use of this tool is very rare, unless it is specifically planned in advance between the parties.
Am I on the right track here?