How to add custom menu item to existing email client on Android?

I have a task to add a custom menu item to Android's built-in email client. This feature shows a custome i开发者_JS百科tem, such as "My menu item", in the menu when the user selects an email in the list view. When the user select this custome menu item, my java code should be called and retrieves the email information, such as sender, recipients, subject, body, attachment information, etc. to do custom job.

I am a BlackBerry developer. I can do this easily on BlackBerry. But I am new to Android. I need to know:

1. How do I add a custome menu item into the existing email client's menu?
2. How do I retrieve the selected email information in the event process?

Any response is appreciated.

Lawrence

---

You cannot do this in Android. You cannot alter another application, and even the native e-mail client counts as an application (everything does). Perhaps with a further description of what your menu item is supposed to accomplish, we can suggest a different strategy that fits in with Android.