Microsoft Outlook font is too large or too small in Reply/Forward messages - Windows
These steps address a situation in Microsoft Outlook when the message text in Reply and Forward messages are abnormally large or small. In most cases, the user did not intentionally make this change.
- Open any Outlook email message and click on the Reply button.
- In the main menu, click on the Format Text menu option.
- On the far right of the Format Text ribbon, click on the Zoom icon.
- Change the Zoom to setting to 100% and click on the OK button.