AppleLink could only do it because everyone, both sending and receiving, was registered with a central server. The last thing I would want to see would be a further erosion of anonymity and privacy on the net. Perhaps we could supply a unique pair of keys for each email, with the retrieval key held on the sender's machine. Only if a second email shows up with the retrieve instruction and the appropriate key would the email would be deleted. It just, apparently, is not an interesting one.
Email needs to be looked at with a whole fresh perspective.
As currently embodied, it is the very manifestation of computing in the 1960s, the decade that launched the Y2K bug. About the only system I could think of that would be worse would be one where you were expected to memorize completely nonsense addresses consisting of nothing but numbers, and then would only be able to communicate with the other person if they happened to be sitting in front of their receiving terminal at the time. Maybe to make it even worse, you could eliminate all possibility of communicating via the visual medium by restricting it strictly to voice. All rights reserved.