
APNS is based on Apple Servers, and Apple doesn't give any guarantee on successful message delivery.
If the app is open (i.e. the user is using the app) while the notification arrives, iOS doesnt show a notification message, you need to handle it.
Notification shows up only when the app is backgrounded or killed. 
Also implement feedback service on your server side; will help you get rid of old unwanted tokens(users who deleted the app or disabled notifications thru settings).
Dont send too many notifications to a device within a short span of time, coz APNS caches only 1 message/device (if the device is offline). So it can deliver the message when the device comes online. Am not sure how long the message is cached though.
Check your certificates that use in other devices.


Apple Push Notification - all messages get sent but not all get delivered
I am looking for a command line way to change the background &amp; foreground colors of all open terminal   (and also for any new terminal, the new settings should be applied).

Using something like setterm -term linux -back blue -fore white -clear
only the terminal in which I execute the command  is affected. I want to change for all terminals, without needed to close/reopen any terminal.

thanks
