Hotmail improves Newsletter filter – Categorizes over billion Newsletters automatically everyday!

We all have subscribed to some or the other Newsletters and we get them almost daily in our Inboxes. They can be anything – maybe product offers, discount coupons, deals, new arrivals, technology updates from various companies etc. So while we cannot really classify them as spam, they keep accumulating in our Inboxes.

Hotmail since many years has been studying Spam and implementing its SmartScreen filtering technology to reduce them. In 2006, in its study, it showed around 30% as Inbox spam. This technology has reduced spam to historic lows of less than 3% as of today. Now with spam reduced to manageable levels, it is focusing on the rest of the Inbox and the results are surprising!

More than 75% of the emails that people report as spam are really legitimate newsletters, offers, or such notifications that you have signed up on a legitimate website and these mails clutter up the Inbox. Hotmail has given a new term to such mails – GrayMail.


Hotmail then trained SmartScreen to identify not just spam, but also specific kinds of graymail – the newsletters which forms about 50% of Graymail.

The SmartScreen filtering has been trained in such a way that it can differentiate Newsletters from Social updates mails like notifications from Facebook or Twitter.

Dick Craddock, Group Program Manager Hotmail in his blog post says –

To get Hotmail to identify newsletters for us, we began by making a list of newsletter characteristics and built a piece of software to extract them from incoming emails. This list forms the model of what makes newsletters different from all other mail..”

“Using a technique called machine learning, we built a system that trained and adjusted the model until it reliably detected most of the newsletters in the reference set. Because the reference set was built from a completely random sample, we knew that the filter’s performance against it would very closely approximate “real world” performance.

It has been so well-trained that the latest release of Hotmail uses Microsoft SmartScreen to identify more than a billion newsletters every day and automatically categorize them as ‘Newsletter’ .

If you are unable to see Newsletter category by default in your Hotmail, let us see how to view it.

Click on the Gear icon near the ‘Quick Views’ > Click on “Manage Categories’ and tick ‘Show the category column in the message list’.

The Category column will now be visible in the Inbox.

You have lots of different categories listed and you can even add a new category and manage them. Various mails get categorized under appropriate categories. If you get Twitter, Facebook, PayPal alert mails in your Hotmail, you can see them categorized under Social updates.  Similarly if you receive Photos, they get marked under Photos category … and so on.

Although Hotmail automatically identifies and categorizes Graymail under Newsletters, they continue to accumulate in our Inbox, creating clutter. For GrayMail management, the New Hotmail has provided powerful tools like Sweep, Scheduled Cleanup, etc. We we learn a little more about these tools in our future posts.

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The author has been a Microsoft MVP awardee in various Windows categories (2006-2016) and currently a Windows Insider MVP. A Technology Enthusiast, interested in anything technical and is committed to Microsoft technologies and products. He is actively associated with various Microsoft online communities, forums, Newsgroups and has been actively involved in Beta testing various Microsoft products and bug submissions.

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