How To Change The Font For Incoming Mail In Thunderbird

How to Set Your Thunderbird Incoming Mail Options

Here’s how to change the look of your incoming mail:

Select Thunderbird > Preferences (Tools > Options on a Windows computer) from the Thunderbird menu bar. Click Display. Select the default font and size you prefer. To change colors, select Colors. When you’re happy with your choices, hit OK to return to the Formatting menu. Select Advanced. Make the choices as desired and hit OK. Uncheck the box next to Allow messages to use other fonts so that your choices will override those of senders.