I'm not convinced we have a wide-spread problem at this point. A lot of our 750 employees have iPhones. I get mail complaints in a hurry because the phone is their first has become place for scheduling and HR issues. Our delivery and order picking associates are all with iPads and iPhones using Microsoft cloud. Problems = 0. My wife's complaints (G Suite and our independent hosting firm family email) disappeared. She only uses native email client.