From Twocanoes Software:
Confused by the array of ports and services that need to be open to use the Apple Push Notification service? Push Diagnostics is a simple to use utility that will quickly verify that the appropriate hosts can be reached on their respective ports from any network you are on. Just open, click, and know. One button interface provides a quick overview of APNs reachability.
- Validates all ports currently used by iOS 5 and OS X Lion 10.7.2 and higher.
- Settings to validate both the test and production APNs servers.
- Detailed results with name, IP addresses, and approximate latency of connections.
- Automatic updates via Sparkle.