Microsoft's MSN Hotmail service has made a suite of tools available to ISPs to help them identify spam traffic carried on their networks. The MSN Postmaster website offers detailed information on email sent to its Hotmail accounts through its Smart Network Data Services monitoring. An ISP can check its range of IP addresses with the service and find out how much mail it sends to Hotmail, how much is eaten by Microsoft's own anti-spam technologies and identify sources of spam and bulk mailing so that network owners can decide on what action to take. Microsoft is also implementing its Sender ID authentication protocols within Hotmail, to verify the origin of email and weed out phishing campaigns. However, Sender ID has been a controversial topic, because while Redmond is keen to have it adopted as a global standard, it also has patent protection over certain areas which it is unwilling to fully open up in a way that software sold under an open-source licence can use. Given that something like three quarters of email servers run such software, it remains a sensitive subject.