I am maintenance a project using UDID and device token to implement push notification for iphone. At first we are using UDID to push, but after that Apple reject other apps using UDID (not our app), so we plan to move all things to use device token instead of UDID. But in our server store many UDID from users, we want to continue using UDID with our server and device token for push notification. Can we keep them both in our server? Do Apple allow that, do we have chance to be rejected from Apple team?
As far as I know, any app collecting UDID will be rejected. If you need to use something like UDID, you can try OpenUDID. But for push notification, it's not necessary to use UDID, the device token alone can do the work. I'd suggest build up a new data system with OpenUDID and device token, or device token alone.