My experience echoes that of the others. I receive abusive emails through MSN Hotmail, but have no way to report abuse without first registering and providing MSN with personal information. (I don't know if those who are members are able to complain.)
Solution: I've filtered out ALL MSN emails. I recommend that others do the same. My filter allows me to return an auto message. I point out, in my message, that the "FROM" ISP, (MSN) permits abuse and does not allow for complaints. I recommend that the sender forward my complaint to MSN.
Agreed, my personal strategy does not affect the giant, MSN. But-- if enough people begin filtering out all Hotmail, MSN may--in that way--get the message. Of this you can be sure: so long as MSN views its current policy, that of making itself inaccessible, then it will continue doing things in exactly the same way. As things now stand, MSN is giving an open invitation to all hackers, smut providers and extremist.