This is what I mean by manual:
http://en.wiktionary.org/wiki/manual#Adjective3. Human initiated or controlled (contrasted with automatic)."Manually send you a key" means that I will send you an email by opening my email app, clicking on the link to your email address to compose a new email, loading a template , creating a new key (multiple steps), pasting it into the email, and hitting send.
Having just listed the steps, it might be worthwhile to write a personal app that sends a new key with the paste of an email and a click to send.