however if you know that the message comes from a trusted source,
you might give it preferential treatment. for instance, you might
allow it to be delivered immediately. if you aren't sure about
the message source, you might refuse to accept the message for
some period of time - a few hours or a few days.
Unfortunately, one of the best uses of email is to contact people
outside your circle. I got a couple of mail messages today from people
I haven't heard from in a while and who I would not have had in my
which is precisely why it's important to not reject such mail out of
I think the main good certification can do is to stop some of the
idiocy mail forging viruses have started.
indeed, if we could just make it easy to trace the source of viruses
(so that we can detect them earlier and make it more likely to catch
them close to the source), that would seem like a big win.