Simple? Aside from GnuPG the other pre-requisites are: A mail server for your domain with the full authority on the user mail addresses for this doma

Simple? Aside from GnuPG the other pre-requisites are: A mail server for your domain with the full authority on the user mail addresses for this domain. A Unix system where you have an account to receive mails to a dedicated mail address and to send mails via the sendmail tool. An account on the mail server will be the best choice. A web server for the same domain to deliver static pages over TLS. Re-direction to a different server is possible The ability to install the latest GnuPG version from source. then the step-by-step instructions go on for several pages.