Richi Jennings of Ferris Research raises an interesting point about the utility of non-delivery notices for the casual e-mail user:"Here's another insight from an 'unsophisticated' e-mail user. We think this is interesting feedback for vendors of e-mail clients. It might appear trivial to e-mail cognoscenti like us, but it's an important human factors observation. It's an area where we as an industry can do a better job. \u00a0"In a panicked phone call, 'my' user told me that he'd sent an important e-mail message to three people. But he'd mistyped one of the addresses and got a non-delivery message back. His question to me was:\u00a0 " 'Did the other two people get my message?' "\u00a0 "Of course, I told him that, yes, they did. But now that I come to think about it, why should that be obvious to him?"Seems like that one ought to be solvable, no?And then there's the matter of so many spammers using non-delivery notices to cloak their junk. Sure, we all can recognize the real from the fake at a glance and simply delete the fake. But the casual user? Must be maddening.