. . . may not be apparent to me. Almost a throw-away line in a weekend newspaper article ( http://www.smh.com.au/news/national/sex-victims-saved-from-court-torment/2007/10/06/1191091420533.html ) states:
"And in a move against internet predators, the laws will create a legal assumption that a person who apparently sent and received an email did in fact do so. This is designed to stop pedophiles and perverts from escaping conviction on a technicality."
The question is, apparent to whom? The average user goes on what their email client displays in the From: field - but of course, this can easily be forged, as can the MAIL FROM: part of the SMTP exchange. I've explained all this before (see Tracing Emails), and even demonstrated it as part of an expert opinion in court.
The problem is that email headers can be forged, either by a sender or a receiver. Unless subjected to detailed examination and tracing, they should be regarded as being of very low evidentiary weight.