Method: Add response key => value pair.
Method: Verify nonce and die if failed.
Method: Verify permission of a user.
Method: Set ajax as success.
Method: Set ajax as fail.
Method: Add snackbar.
Method: Get and set request.
Method: Send ajax response.
Method: Prepare template for email body based on event type.
Method: Get email ids of user. If email passed then add it to email property.