sendmail can't send to hotmail address

[jc at trillian.mit.edu (John Chambers)]

I've been sending email mostly with a little perl tool that
I  wrote,  which  is  loaded  down  with lots of diagnostic
stuff.  For some time (at least a few months), I've noticed
it's reports on hotmail.  MX queries for hotmail.com return
a long list of mail servers, but most of them at any  given
time  refuse  connections.   Others accept connections, but
don't respond with any text. Occasionally one down the list
actually works.

My impression is that hotmail's DNS service  returns  fixed
lists of MX records, but at any given time most of them are
offline or too busy to  answer  or  in  some  other  zombie
state.

Sometimes all of them fail.  My program falls back on  just
"mail.hotmail.com",  and  sometimes  that one works.  Or it
also hangs or refuses the connection.

They're one of the nastier email services around.