>Would love to hear an expert opinion on why this exchange even took place in any traceable from.
Notice that the initial contact came from Steve via phone, and the Palm email is intentionally saying "no" in a traceable form since they are not doing anything wrong. A "yes" would probably have been by phone. Steve also doesn't say anything incriminating in his email response, just vague threats.
"Then the Palm CEO sent a traceable 'no', in the hope that the Apple CEO would be intimidated into silence. Instead Mr Jobs consults with his lawyers on wording and replies 'I am well aware I threatened you, and here is my threat in black and white'." from the book 'When Elephants Play Chicken' by J.R. Hartley.
Notice that the initial contact came from Steve via phone, and the Palm email is intentionally saying "no" in a traceable form since they are not doing anything wrong. A "yes" would probably have been by phone. Steve also doesn't say anything incriminating in his email response, just vague threats.