[plug] [OT] hotmail hostility

[sol]

Sorry, this is an off-topic question, but if anyone is likely to know the 
answer it is - ironically - you guys/gals :). Plus it could open up a 
fabulous opportunity to bitch about Micro$loth.

An email sent via Mailman to a mailing list just got a reply from 
postmaster at mail.hotmail.com saying:

"This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed."

It then listed a fairly long list (over 50 at least) of addresses which failed 
to receive the mail. Further investigation about the error states that:
Original-Recipient: 
Final-Recipient: rfc822, dodo at hotmail.com
Action: failed
Status: 5.0.0

This is repeated against the names of each recipient that did not receive 
email.
Has anyone had any similar problems with hotmail? Is it refusing to have these 
posted because it thinks that it is spam? Has anyone heard anything about the 
hotmail servers being tricksy lately?

Ta,
sol