In Mobile settings, make sure that notifications are on for JIRA Mobile.
Make sure your that the ports 2195, 5223, 2196 and 443 are enabled(push Notifications are sent from your JIRA server to the Apple APN Gateway) and they are not blocked by your firewall.
On a side note, for Android devices, the Google Cloud Messaging (GCM) service is used. JIRA server needs to be able to make outbound calls on ports 5228, 5229, and 5230.
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