e-mail sent verification

I need to know if there is a way to verify that a sent e-mail message was actually received by the intended recipient. I am not talking about a "delivery receipt" setting for future e-mail, but rather, a past message where no such options were enabled. I have an archived e-mail for which I need to verify validity, and all I can see in the header that could be a unique identifier is a key labled "message ID." I asked my service provider (Earthlink) if it is possible, but I was told by a support tech that there is no way to trace the information. He further said that the same identifier key might actually be assigned to another message going through their system at some point in the future. Is this correct? It didn't sound quite right to me, hence my reason for approching the experts. To make matters more difficult (and archaic), the message in question is a year and a half old, and was sent from an older machine on a 16-bit platform with Netscape 3. Can any kind of a viable outgoing trace, at any level, be executed under these circumstances?