Open TOOLS menu. (Alt T) which is in between Format and Table Menu. Select customize. You'll find Toolbar window
In toolbar tab uncheck the email option and hit close button.
To close the email pane in Word, first you must open the Tools menu. You can do this by pressing alt T. Then you must select customize, and in the toolbar menu, uncheck the email option.
Open TOOLS menu. (Alt T) which is in between Format and Table Menu. Select customize. You'll find Toolbar window In toolbar tab uncheck the email option and hit close button.