email alerts are near worthless, most of the time the email w/the picture dont come in is because your MailServer is throttling back the emails since it sent 3 at a time, and guess which one is the largest, the one w/the image.. there are configuration options to reduce the frequency of snapshots taken, needs to be set to like 10s.. but missing snapshots is still gonna happen unless you run your own mail system w/out anti-spam throttling.
Push Notifications w/the Mobile Apps combined with IVS Rules works much better and faster.