This feature depends on your hosting provider setup, it is completely outside of Automad.
Here's a guide about how something like this could be configured:
flow: email triggers php script which would write the contents of the email to a new file in the Automad pages folder.
Searching on the hosting company I use, Dreamhost (I am not recommending them), reveals this script that is similar enough I could modify it to do this sort of email to Automad thing:
It would be very difficult to do as a plugin as each person hosting setup is different. With Blogger they can do it because they control their own server and they they do it once for everybody.