Just like any built-in OS X Lion application, there’s a lot of flexibility in Mail’s toolbar. It’s quite easy to customize the Mail toolbar that way you want it to be and put the functions that you use the most within easy reach, or a couple of clicks away.
The settings and preferences of Mail behave similarly to other applications so if you have customized the toolbars for other apps such as Finder and Preview, then you can do this with your eyes closed.
Adding icons to the toolbar only involves a little clicking and dragging. To do so, put your cursor on a blank area of the Mail toolbar Control-click or two-finger tap the area to be able to see the options. Select Customize Toolbar from the options in the menu. A panel of icons will appear and simply drag your selected icon into the toolbar. Click Done when you have added all the icons that you like.
You can also rearrange the icons in your toolbar if you are not happy with their placement. Simply click the icon and drag it to its new location in the Toolbar. And if you want to get rid of an icon from the toolbar, control-click to select the icon and choose Remove Icon from the options given.
As you can see – Customizing your Mail Toolbar is easy and helps to improve your workflow.