Blackberry SDK, Modifying messages

In an earlier article, I stated that I liked the BlackBerry SDK, and one of the things that I liked that the SDK seemed complete, in that it supported and documented how to do things that are "hard to do" (e.g. Bluetooth support).

I decided that a thought experiment was in order: could I modify email messages as they are sent?

The BlackBerry SDK makes this fairly straightforward: implement the net.rim.blackberry.api.mail.SendListener interface, which has a single method:

public boolean sendMessage(Message message)

By implementing this method, you can modify the message as you see fit (Message is what you think it is!), and even block the message by returning false from the method.

Now, based on things that Apple has said, I don't believe that the iPhone will support this type of development-- modifying the default behavior of the built-in applications.

Based on what I have seen in Android, it does look like this would be possible there (I haven't looked extensively, however).