Keep in mind, though, that you should use plain text or maybe HTML formatting unless you know the recipient also uses Outlook.
Use Word as Your Default Email Editor in Outlook
To set Word as the default editor for email messages in Outlook:
- Select Tools | Options from the menu in Outlook.
- Click on the Mail Format tab.
- Make sure the Use Microsoft Office Word 2003 to edit e-mail messages checkbox is selected.
- In versions before Outlook 2003, the text reads Use Microsoft Word to edit e-mail messages.
- Close the dialog.
Outlook 2007 and 2010 always use Word for editing.