When Jack at Hotmail replied on Wednesday, Oct. 16, he included
the LSTSRV-L address in his reply so I thought his message would
show up here but apparently it didn't.  Here it is:

Hi all,

This is Jack at Hotmail escalation.

OK, here's what's happening. We accept your message and it goes on our
spoolers. Something on our SMTP servers messes up the time stamp on one
or more messages in that same que. The spooler tries to enumerate all
the messages it's got and can't, so it starts over. And it still can't.
48 hours later the spooler crashes from having an insanely long que, or
the admin finally tracks down what spooler is clogging the system. Then
it reboots and notices that all of your messages have been in the que
for 48 hours and that their TTL has expired. It then bounces the
messages back to you with a generic 5.0.0 error.

Right now we are putting together a QFE (basically a system wide policy
change) that will allow the spoolers to disregard any individual message
with a defective time stamp and then go ahead and process the rest of
the que. That's the good news. The bad news it that this QFE cannot go
into effect for at least 2 weeks.

Meanwhile, at least we know what the problem is. For you the solution is
to treat all of our 5.0.0 errors as if they were, say 4.5.1 errors. In
other words, just try to resend the messages. The odds are that you'll
get through on a second try as you'll end up on a different spooler.

Jack, MSN Hotmail support