Thunderbird
- In the top-side menu bar, select "Tools", then select "Options" from the drop-down menu.
- Click on the "Composition" tab, then the "General" tab underneath Composition.
- Click on the "Send Options" button.
- Find "Text Format", and select "Send the message in both plain text and HTML" from the drop-down menu.
Consult the image below - all formatting should appear as it does in the image.

