The easiest is to have your raspberry pi get all detection pictures, and then it will decide which ones to send over email (as opposed to JeVois deciding to only send some pictures to the pi). Then see here:
http://jevois.org/tutorials/UserArduinoBlink.html
http://jevois.org/tutorials/UserArduinoYOLO.html
So you write a python script on your raspberry pi which does this:
- open video capture from JeVois using OpenCV VideoCapture with the correct resolution and frame rate
- loop forever:
- grab a frame
- receive serial messages from JeVois
- if serial message corresponds to desired object, email the frame
Also see this great project by Peter Quinn:
https://hackaday.io/project/163391-front-door-cam