The filter dialog box, as shown below, is split into three sections, each of which is explained below the image.
The image above has been split into three sections for your understanding.
1) To trace a header you have to first select the first option, as shown in the image above.
2) The text box shown above is where you have to paste the email
header you want to trace (click here for a list of tutorials that help you extract
the email header)
3) Once the header has been pasted into the Email headers section
click the trace button, as shown in the image above.