How to fix if the "Mail" button is missing in IE

You can customize the toolbar to add or remove icons, including the mail icon

• Right-click the Star icon in the IE window
• Choose Customize Command Bar
• Choose Add or Remove commands
• Click on the Read Mail item in the Available toolbar buttons list
• Click the Add button to move the button to the Current toolbar buttons list
• Click the Close button

If the button still isn't visible, it may be pushed off the side of the screen.  To fix this:

• Right-click the Star icon in the IE window
• Uncheck Lock the Toolbars
• Drag the dotted splitter in the command bar to the left until all of the buttons are visible