A monk peers through a tube into what is now a hole in the manuscript. Chances are, he is looking at the clock in the sky at night around the year 1,000. (He is Swiss, after all.)
Part of the constellation Ursa Minor, Hevelius's 32nd of Camelopardalis seemingly travels in circles around Polaris at the center (like all respectable stars do in the Northern Hemisphere) in a manner that allows one easily to tell the hour, say for prayers, when the sun is down.
Now, do you want to gaze through a tube, too, metaphorically into what is left out of an email's regular showing and tell not only the time the message might have been sent but quite a bit more as well?
›› Want to know where all the junk mail is really coming from? Find out how the source of spam can be determined using an email's header lines.