Ok so im starting this feature request based on a previous experience with a change that you ( Canary ) made. You recently made an assumption (not sure what this was based on) that all users wanted their devices to not record while users were at home. You made this change a default setting im guessing across your entire platform for every user. Needles to say i was less than impressed with this and the way that this was communicated !
The change you made meant that one of my cameras that I specifically want to record at all times suddenly stopped recording ! This personally caused alarm for me as I have a very good reason for having this camera on at all times.
Anyway I dont believe you should be making global changes across your platform like this, once users have their setup, they configure accordingly and this should not be changed. If you have a feature you wish to showcase or re-iterate to users than this should be communicated, sadly these days email is no longer an acceptable method of communication for such correspondence as the barrage of spam and everything else that comes through means these will more than likely be ignored !!!
So what im suggesting here is that you use your notification platform to send these types of informative messagess direct to users devices, not only will this raise a notification on the phones but im guessing your engagement from end users will increase due to the very nature of the product ( HOME SECURITY ) I for one jump when I get a notification from canary, not only do i jump but i pay attention, im not saying flood us with sales /marketing info. But any important changes you feel your going to make could be communicated this way, and also potentially give us an option to opt out of the change rather than just applying it and potentially causing chaos to thousands.
Hope this helps in someway shape or form.