Mail Server Flaw Opens MS Exchange to Spam

bl8n8r writes: " Exchange 5.5 and 2000 can be used by spammers to send anonymous e-mail. He says even though software Microsoft provides on its site certifies that the server is secure, it's not. There are dozens of messages--with subject lines such as 'Open relay problem' and 'We are sending spam?'--on Microsoft's Exchange Administration newsgroup, sent by information system managers who haven't been able to staunch the flow of spam from their servers. 'It is really inexcusable for a company that claims security is its top priority,' he said." If you are using vulnerable versions of Exchange, and have been hit by a Code Red variant, you may want to insure your 'guest' accounts are still disabled.