How can send mail to user when admin changes a value in my models?

here is my models.py https://codeshare.io/aYxPZE

I want to send an email to the user when his/her post has to approve/reject.
#I can also send mail when a post created.
this (line 10) value can change only admin from admin panel.

can you share me your Github project link or tell me how can I do that?

#I am new at Django

You can use Django Signals to send an email when your object is saved.

Take a look here and here.