We have been having difficulty sending email to hotmail.com email addresses. This started several weeks ago and was tracked to a computer computer that was indeed sending out spam - but has since been resolved. Normal measures to contact MSN/Hotmail have gone nowhere. We've received the run-around from their support drones.. They've even went so far as to silently drop all email (while reporting successful delivery). We've submitted the forms at their postmaster.live.com site (and been rejected).
Oddly enough - the servers that they are blocking don't show up on their SNDS service.
Please contact me offlist so we can get this resolved.