embed entire post into email notifications

There isn't built in functionality to do what you are describing, but it would certainly be possible to implement this as a customization.

What you could do is create your own custom shortcode that accepts a post id being passed to it as a parameter and have that shortcode then return the post content for that id as the output of that shortcode.

The email notification message supports shortcodes so you could then use that shortcode in the message and where you pass it the id you could use the embed post id merge tag.

Here's the WordPress codex page on shortcodes:

http://codex.wordpress.org/Shortcode_API

I'm not sure what your skill level is as far as WordPress development goes, but the above would be pretty simple to implement for a developer that does understand how to create shortcodes and query/return post content.