How to Add an Email Signature in Thunderbird

To add a signature in Thunderbird, you can either paste your copied signature straight into the account’s signature box, or save it as an HTML file and point Thunderbird at it. The paste method is faster for most people. Here is both, step by step.

Method 1: paste it into account settings

1. In the signature generator, build your signature and press Copy signature.
2. In Thunderbird, open the menu and go to Account Settings, then select the account on the left.
3. Tick Use HTML under the signature options.
4. Click into the Signature text box and paste (Ctrl+V or Cmd+V). The formatted signature appears.
5. Close the settings. Thunderbird applies the signature to new messages from that account.

Method 2: attach a signature file

If you prefer to keep the signature in its own file:

1. On the generator, copy the signature HTML rather than the formatted version.
2. Save it as a plain .html file on your computer.
3. In Account Settings, tick Attach the signature from a file instead, then Choose and select the file.
4. Thunderbird reads the file each time, so editing the file updates the signature.

Keep images working

Thunderbird shows signature images by loading them from the web. A local image works on your machine but breaks for everyone you email. Host the photo or logo at a public URL and paste that link into the generator, so recipients see it too. The reasoning behind this is covered in HTML email signature tips.

Test it

Compose a new message and check the layout, the image and the links. Send one to yourself and open it elsewhere to be sure it travels well.

Build your signature now with the email signature generator, then drop it into Thunderbird.