Change size of text - Outlook
To change the font type/size of incoming plain text messages, follow these steps:
Choose your version of Outlook below:
- Go to Tools > Options.
- Choose Mail Format Tab.
- Click Stationery and Fonts button.
- Go to Composing and reading plain text messages section.
- Click Font... button.
- Make desired changes.
- Click OK.
When you set a default font, every new message you create uses that font setting default. To change this setting in Windows:
- Go to File > Options > Mail > Stationery and Fonts...
- Select the font you want to change
- New mail messages - Sets the default font for original messages you compose.
- Replying or forwarding messages - You can have a different font on messages you're forwarding or replying to. This setting is mostly for the two check boxes that let you mark your comments with your name (or other text) or with a different color of text.
- Composing and reading plain text messages - Plain text messages will be received by the other person with a standard font, but if you want to use a nicer font when you're writing the message you can. Just understand that font won't be sent with the message.
- Select the options that you want to apply to the default font, such as font style and font size.
- Select OK all the way back out to save your changes.
More help from Microsoft
For more information on changing or setting the default font in Windows, Mac and Web, please see this Support Post from Microsoft.