Where can I find the mail headers in Thunderbird?

The mail header is a piece of text coming with your e-mail message that cares information about that message. You can use it to try and find out the message path, or to troubleshoot issues with sending/reaching the recipient. The headers look like nothing different than a piece of code, so most mail clients will not show them by default. To uncover them, follow the steps in the tutorial bellow:

1. Open your Thunderbird.
2. Double click on a message to open it.
3. Click on ‘Other Actions’ > ‘View Source’.
4. A new window will open together with the body (message) and headers.