Massive Mail Improvements in iPhone 4.0 OS.

Many of the frustrations of Mail of the iPhone appear to be resolved.
Here are some of the hard and fast details:
- Fast inbox switching, organize by thread.
- More than one Exchange account.
- Unified inbox: Customers can have multiple e-mail accounts and they all can show up into one inbox.
- Encrypt all of your e-mail and attachments with your pin code