I'm not sure how the 'actually delivered' would be enforced. Does Google have an affirmative requirement to deliver a 3rd parties message? I hope not.

My gmail address received 35 emails yesterday (which didn't get spam filtered). All but 3 of those got auto-archived by the filters I have in gmail. I would love google to just do this automatically.

Practically I might need another message or two a week that didn't hit my inbox.... but that's fine as long as it's as it is still searchable.