Netserve Service Status

We are seeing a lot of mails in at the moment about hotmail and MSN rejecting mail. We are seeing clients mailing in headers that are not just from us, including the bigger players; Blueyonder are currently also sharing the pain. We are 'assuming' they are testing some new block listing (similar to the harshness that is AOL) or their servers are sick.

550 Your e-mail was rejected for policy reasons on this gateway. Reasons
for rejection may be related to content such as obscene language, graphics,
or spam-like characteristics (or) other reputation problems. For sender
troubleshooting information, please go to http://postmaster.msn.com. Please
note: if you are an end-user please contact your E-mail/Internet Service
Provider for assistance.
554 5.0.0 Service unavailable

Unfortunately they are the ones rejecting so we are unable to fix this for you. We have contacted MSN and are expecting an automated reply within the week. We should keep in mind that these are supplied as free services.

[update 12:26]
We are registered with Hotmail/MSN SDNS service. The information gathered from this suggests that clients with accounts set up to forward to Hotmail/MSN addresses have received spam that they have requested to be forwarded and marked it as junk - causing our server that delivered it to be blacklisted.

Currently our spam scanning servers are not listed, however the master relay server is.

The issue here with the Micro$oft system is that they are marking the last relay as opposed to the source of the spam (although all headers can be forged). This is a similar situation as is presented with AOL currently. Small solace can be taken from larger players currently also being blocked.

[Monday Update] We have started routing mail bound for to a dedicated IP for relay to Hotmail - since it is not on their block list. However, once it is blocked this situation will resume. Options include investing in scanning to relay to solve someone elses blocks, or preventing customers from setting AOL or Hotmail addresses as their destination for non scanned forwards or wild-card redirection.
Current situation mails via relay or from the web servers are being rejected. Systems mail is getting out.
IF YOU ARE A HOTMAIL USER - please contact Hotmail / MSN as we are delivering the service and they are rejecting it. Request that the block is removed for the subnets 195.69.95.0/24 and 94.0/24, or that you are at the very least able to whitelist the mail you require.