Hi Kenneth,
I purchased my first iMac in 2015, a 21.5 (2013) and I bought the first generation wireless keyboard, magic mouse 1, and a Belkin Wireless Keypad. I have had the same issues you mention in your post of 03/2/17 repeatedly. First Apple Care told me it was because I had a cordless phone on my desk next to my iMac. I was using the current operating system that was available in 2015. I cannot remember the name. Each time an update was offered, I updated my iMac. I moved the cordless phone out of the room. The issues mentioned continued to occur intermittently. I also had the problem of by touching one key on my Apple wireless keyboard it would generate multiple characters being entered in the password area to get into my desktop on my iMac. Pressing delete would not help. In fact, it made it worse. I would have to do a hard shut down to get rid of the characters. These issues didn't occur every day, but when they did, Apple Care always blamed the hardware in the room, my cordless phone, the electric wiring in my building's walls, my microwave (which was 50' away and with 3 walls between them), my Belkin wireless keypad, my wireless keyboard, my Magic Mouse, my Airport Express, My Airport TimeCapsule, etc. They had me get out my old Windows wired keyboard and Windows wired mouse and connect them to my iMac. The issue would not repeat using a wired keyboard and mouse. They told me to move because it was probably the wiring in the walls of my building. I moved. The issues continue. Also, sometimes when I am creating a Pages document or typing information into a website using Safari as my browser, tiny boxes would appear above the last letter typed, and there would be 5 or 6 weird characters offered above the letter I had typed. The only way to get rid of all the boxes was to either choose one box, or delete my document or close the web page, and start all over again. Apple has replaced my keyboard at least 4 or 5 times, and I think I am on my 4th Magic Mouse 1. Today I finally spoke to a senior advisor at Apple Care who said it is a setting somewhere on the computer that corrects some of these problems.
They said it was the heat from my hands that was causing the emails to inappropriately delete themselves while my hand was over the mouse but not touching it. We ended up changing my emails to be viewed the old way, and we changed my mouse settings.
The first two pictures are available in system preferences under mouse. The third picture is available in mail under preferences and viewing. Changing the view to the classic layout has stopped emails from being inappropriately deleted. As for the other stuff that is occurring, I can categorically say it is not about the electric wiring in the walls, or the cordless phone or the microwave or the other devices in the room or the wireless devices you are using. It's a setting in the software, and Apple engineers will have to figure this out. I would keep writing in to Apple on the feedback page, and if you have Apple Care, keep calling them. Ask for a senior advisor when you call in. Never talk to the first level person with this kind of issue. They do not know how to fix this. They will send you a new device, and that will not fix the problem. They sent me an Apple wired keyboard also, and I tried using it, but I hate the wire. I went back to using my wireless devices. I hope this is not confusing. I have tried to explain clearly.😉 RRR
