This article explains how to reveal headers that are normally hidden in emails in Mozilla Thunderbird. The header can help you troubleshoot email problems.
How to Show Full Email Headers in Mozilla Thunderbird
All emails consist of two parts: the header and the body. The standard header, the part you normally see, usually lists the sender and recipient of the message, the date, and the subject. However, behind the scenes, the header contains much more information, such as the path the message took from sender to recipient, the IP address of the sender, and the priority of the message. This information is not exactly easy to interpret and is usually of no interest to the recipient, so it is hidden.
When asked to provide all message headers to stop a spammer, resolve an email problem, or if you're just curious, you can reveal all the hidden information.
Select a message in the reading pane to open it in a new tab or window.
