Full email translation (similar to whole page translation)

There should be a context menu option to translate whole email.

However the "whole page" translator can't be used since the email is not a page so those "page translation" services can't access it. So the only way to translate the email is to detect the email text and paste it in the default translator.
It should detect and translate only the"new" part of the email and ignore the rest of the old conversation. This may be a challenge since reply could be at the top or at the bottom.