If your iOS device goes to sleep too fast, consider adjusting the auto-lock settings, i.e. increase the time of inactivity after which your phone will go to sleep.
If your iOS device runs on iOS 9 or earlier:
If your iOS device runs on iOS 10 or later:
If you don’t receive the email in the next 2 minutes please check your junk folder, and add [email protected] to your safe sender list.