Just do the following steps:
- Open Mozilla Thunderbird
- Click on your email account name in the folder tree in the left panel
- Click on View settings under the Accounts section
- Scroll down to Signature text and select the Use HTML checkbox
- Copy the source code of your signature, directly from the eMsg application, or from the email you received, by right-clicking in the browser and choose « View the selection source
- Just paste the copied html text of your signature
- Click OK to confirm changes
Create a new mail and choose the corresponding signature, it should appear with bells and whistles!!!