You can change your default font for messages in Outlook Web App, previously called Outlook Web Access, in the Message Format section of the Options page. The message font options you select automatically apply to the body of messages you compose in Outlook Web App. You can also use the text-formatting toolbar while composing a message to change the format and appearance of your text. If you use Microsoft Exchange, your system administrator can restrict and change the default settings in Outlook Web App.
Change Message Font Options
Sign in to Outlook Web App, click the "Settings" gear icon at the top-right of Outlook Web App and then select "Options." You can manage the most common Outlook Web App settings on this page.
Click "Settings" on the left sidebar. Scroll to the "Message Format" section and then select a font in the box under "Message Font" containing the current font's name. For example, click "Calibri" to expand the list box and then select the font you want to use. You can also adjust the font size in the box to the right of the current font's name.
Click the "Save" button. The next time you compose a new message in Outlook Web App, the message font you selected will be used by default.
Format Font in Messages
Sign in to Outlook Web App and then open a message draft, reply or forward a message or click "New Mail" to compose a message.
Enter some text into the body of your message. The text reflects the font options currently selected in the formatting bar above the body.
Select the text you entered using your mouse and then change the font options in the formatting bar above. To change the font, select a different font name from the box containing the name of the current font. For example, click the "Calibri" box and then select "Arial" to change the message font to Arial. You can change the font size in the box to the right of your current font. Use the other commands in the formatting toolbar to change the appearance of your font, including "Bold," "Italics," "Underline," "Font Color" and "Highlight."
The light version of Outlook Web App only supports plain text in email -- you cannot format your font, add inline images or create hyperlinks. To enable or disable the light version of Outlook Web App, click the "Settings" gear icon, "Display Settings" and then "Outlook Web App Version." Toggle the check mark in the "Use the Light Version of Outlook Web App" box and then click "OK" at the top. Sign out and exit your browser. Your changes to the Outlook Web App version appear the next time you sign in.
To change the font colors in your Outlook Web App theme, click the "Tools" gear icon, select "Change Theme," select a theme icon and then click "OK."
Some Outlook Web App settings may be globally controlled by an IT administrator.