any limitation push notification via APNS or C2DM?

Question

In enterprise, we will send push notification to 17,000 employee. They have smartphone(iOS, Android).

We expect to send about 18 millions push notification per year.

Answer 1

The general quota for Android's C2DM is 200,000 msgs per day for regular sign ups. However, if you need more, you will need to contact Google to arrange. More information here: http://code.google.com/android/c2dm/quotas.html

Answer 2

Not sure about C2DM, but APNS has no limit I've found yet. I send roughly 7 million push notifications a month through my servers, yet to see a problem.