Originally Posted by waltinsocal

Not sure about the deduction process, but you are correct about the posting. The swiping of the boarding pass leads to a real time posting of the miles if you are posting to a Delta SM Account. I know this because I have logged into my account after boarding and have already seen the miles for that leg of my flight. I think a couple of times they weren't there for whatever reason, but they have never failed to be there when I have checked again after landing.