To change the default font for outgoing email in Mozilla Thunderbird first go to the Tools menu and click Options:
![Thunderbird Tools Options.JPG Thunderbird Tools Options.JPG](https://www.emailquestions.com/data/attachments/1/1338-fca2f5f1f1a2f911849476357b6a9bee.jpg)
In the Composition configuration click the general tab and then select a new font in the HTML section:
![Thunderbird Composition General HTML Font.JPG Thunderbird Composition General HTML Font.JPG](https://www.emailquestions.com/data/attachments/1/1339-e73a79a777d985912223b49ad71e0a8d.jpg)
It is also a good idea to check the Send Options to verify that recipients will get plain text if they identified as not being able to receive HTML email.
![Thunderbird Tools Options.JPG Thunderbird Tools Options.JPG](https://www.emailquestions.com/data/attachments/1/1338-fca2f5f1f1a2f911849476357b6a9bee.jpg)
In the Composition configuration click the general tab and then select a new font in the HTML section:
![Thunderbird Composition General HTML Font.JPG Thunderbird Composition General HTML Font.JPG](https://www.emailquestions.com/data/attachments/1/1339-e73a79a777d985912223b49ad71e0a8d.jpg)
It is also a good idea to check the Send Options to verify that recipients will get plain text if they identified as not being able to receive HTML email.