Some characters, such as quotation marks in Outlook for Mac OS X, may not display correctly. This is because the characters may be encoded with a text encoding scheme that is different from the default encoding used on other computing platforms. You can force Outlook to use a different “Preferred encoding” by following the steps below:
1) In Outlook choose the Preferences -> Composing menu item.
2) The Preferred encoding for new messages option should be set to Unicode (UTF-8).
3) When you have changed the text encoding setting, close the window and your changes will be saved.