There’s an extremely quick and easy method to set up push email on your iPhone, iPhone 3G, or iPod Touch, without buying a MobileMe subscription. Although this method doesn’t provide actual push functionality, your iPhone will automatically check for new mail every 15, 30, or 60 minutes – whichever time frame you choose. If there’s new email, you’ll get a red number right over your email icon.
Follow these simple instructions:
1. Go to Settings
2. Go to Fetch New Data
3. Turn Push "On" and Choose the Frequency
Note: For better battery life, fetch less frequently.