Hotmail has bounced many connections with a 'fatal' error code: 550
SC-004. This happened at about 0015 on 19 March (UTC).
Looking at Hotmail's error page at:
http://mail.live.com/mail/troubleshooting.aspx#errors says it was
rejected for Policy reasons
The result is many (all?) hotmail
For those interested it looks like this happened for at least a couple days
and was resolved yesterday (at least so much as we were removed from the
blacklist), the bug ( there was some discussion with ops prior to it trying
to track down the issue as well) is at
