Step 1 — Create your signature
Create your email signature in Mirosign.com.
Step 2 — Open Thunderbird signature settings
Open Mozilla Thunderbird
Click on your email account name e.g. firstname.lastname@example.org and then on View settings for this account option under the Accounts section.
Check the box for Signature text: ☑️ Use HTML (e.g., <b>bold</b>)
Step 3 — Paste signature
Return to Mirosign.com in your browser and click the yellow copy HTML button
Return to Thunderbird settings and paste into the box below Signature text and click OK
Select Write a new message
Your Mirosign email signature will appear in the new email window like this: