Do you want to have your Mail.app to organize your conversations like gmail? If so its a very easy thing to toggle on and off. All you have to do is:
- Right-click in the toolbar.
- Choose “Customize Toolbar…”.
- Add the “Threads” button.When you click on it, you inbox will automatically adjust, sorting everything by conversation.
- Clicking on the blue arrow at the left of a message (a message that contains many more) will let you see every email in the thread.
What makes this even better than Gmail is that it is really easy to activate or deactivate it.