Microsoft's vastly interconnected ISP and portal, MSN, has become easy prey for spammers due to several poorly-protected mail (SMTP) servers to which outsiders can connect easily for a free, anonymous ride, according to a bulletin on the Mail Abuse Prevention System (MAPS) Web site.
"We have recently received a number complaints about open mail servers on the MSN system. This means that the servers will accept mail from people that do not have valid MSN accounts, and also allow them to send the mail to addresses not on MSN's domain," the bulletin says. "For obvious reasons, open mail servers are ripe for abuse by spammers."
The organisation has placed the several mail servers in question on its Relay Spam Stopper (RSS) list, until MSN can manage to correct the problem.
MAPS is a California non-profit organisation which maintains a database of spammers, which in turn has resulted in a steady accumulation of lawsuits by those who believe MAPS is interfering with their businesses.
In this case, MAPS has caused some difficulty with legitimate mail on the MSN network, which it says it can do nothing about because the RSS can't be tweaked with enough precision to avoid throwing out the baby with the bath water. The compromise here is to block all traffic from individual servers clearly associated with large quantities of spam. Unfortunately, this is the only way to defeat the offending pink substance with any degree of confidence, as rules-based filters are even less precise, often stopping a good deal more legitimate mail.
The RSS is a DNS-based list of spam-relaying mail servers for use by ISPs and others running SMTP servers. "If you run your own mail server, you can configure it to utilize our list, if you'd like to refuse mail from these types of servers. Please note that if you do this, you may also refuse some legitimate (non-spam) mail, as some 'bad' servers may also have good users on them," MAPS notes.
The organisation has already received several complaints from those whose regular mail has been interrupted as a result of adding MSN to the RSS. The organisation recommends applying pressure on MSN to get its act together quickly. "As soon as these [MSN] relays are secured, we will be able to remove them from the RSS," MAPS says. ®