I still think the missing opportunity with e-mail was for the USPS (back in the US-dominant internet days) to take a leading role and implement "e-stamps." Provide a subscription service that managed a per-user account, cost a 1¢ stamp to send a message, and guaranteed delivery of messages received with a 1¢ stamp on them -- with the received stamp value being put in the user's account, so a user who received more ma…
> We could have had a world without spam I doubt it. USPS charges everyone to send snail mail, and I get plenty of spam in my mailbox. I end up with way more spam in my snail mailbox than in my email inbox, since the latter has filtering.
There's obviously a lot of physical waste in this day and age and it's arguably small by comparison, but the paper waste from mail spam still disgusts me.