Oh, and here I though this discussion was about git. But you're talking GitHub.
https://opensource.stackexchange.com/a/380/30121
(Is this pedantic? I guess in a lot of contexts. But you talked about the original, intended way to do it. So it seems on-topic here.)
In git syntax, the command is "git request-pull".
What's that in natural language? Perhaps... "A pull request"?
What kind of email is that?