I've noticed a new behavior, which may be a bug. One camera (alert image) that does not have any groups assigned is showing in the "All Cameras" view in the app when triggered (right column). The logged in user only has access to certain groups, and this camera does not show in the camera ...

The best way to tell what's going on is to open one of the e-mail messages and view the full message headers. It will show the full mail flow and all server handoffs along the way, with timestamps so that you may be able to tell where its being delayed.