Note: Make sure you are using either Google Chrome or Firefox during the installation process.
Create your email signature on NEWOLDSTAMP.com and follow these simple steps to install it in Thunderbird.
After you finish creating your email signature, click Save and Install button under the signature preview.
Or if you have saved your signature priorly, hover over your signature on the dashboard and click Use button.
Select the Other icon in the list of email clients.
Choose the HTML tab and copy the HTML source code by clicking Copy and proceed button.
Then open your Thunderbird App on your computer. Click Menu icon in the top-right hand corner, hover over the Options in the menu, and select the Account Settings option.
Put a checkmark next to use HTML option and paste the signature into the Signature text field.
Alternatively, select the Attach the signature from a file instead and click Choose. Select the HTML file downloaded from NEWOLDSTAMP and confirm the changes.
Save the changes and compose a new message to see your unique signature in action.
Congratulations! Now you will see your new signature in every email you send with Thunderbird.