[e2e] was Re: A message to authors - nsdi

[Sharad Agarwal]

> But couldn't that kind of process also be applied now, just with a NACK
> (because, being a spammer, I'm the sender and receiver)?
> I get some free email accounts and send spam everywhere, and check
> (maybe automatically) if it made it - if it didn't, I'll know.

True, you can do that. But only to the Hotmails and Yahoos of the world. You wouldn't be able to do that to say the microsoft.com or eecs.berkeley.edu mail systems. With the ACK or NACK system, then you could test any email domain that implements it.