Step 1: Create a new email with clicking the File > New > Mail Message.
Step 2: In the Message window, click the Office Button at the upper-left corner > Editor Options.
Step 3: In the Editor Options dialog box, click the Popular in the left bar,
Step 4: Click the Language Settings button.
Step 5: Click the Display Language tab, then click the Display Microsoft Outlook menus and dialog boxes in box and specify the language from drop down list.
Step 6: Click both OK button
