> A long digression, I'll admit, but that's an SMTP/MTA issue that even
> people who know what they're doing aren't able to cleanly fix.  How is
> a piece of software supposed to deal with it?

Don't push messages in the first place?

> > Mailing lists made sense back when everyone wasn't on the net full time,
> > or even directly connected to the net at all, (UUCP, FidoNet, Bitnet,
> > Compuserve...) but it really doesn't anymore.
> 
> Dial-up users still exist.  Even if we assume that everyone on this
> list is online full-time (which I think is highly unlikely), we're a
> highly-technical segment of the population here and can't be expected to
> represent the average joe in that aspect.  Not to mention that, until we
> have ubiquitous public wireless coverage, my laptop isn't (and won't be)
> on the net full time, even if my other machines are.

Red herring. Any decent mail/NNTP client does 'offline' mode these
days, whereby they will mirror a mailbox/newsgroup on local storage.
There's no reason to be 'pushing' thousands of duplicate messages
around the 'net anymore. Clients can 'pull' whenever it is convenient
for them to do so . Its pretty well established at this point that
"pushing" is not a good way to go about mass distribution on the modern
internet. Pull is how the web works. And look at how successful
PointCast, Marimba and Netcaster were...