The pitch: Clutter is a feature of Microsoft Exchange / Outlook (both on-premise and online) that moves your low priority messages out of your Inbox so you can easily scan for important messages. Clutter analyses your email habits, and based on your past behaviour, it determines the messages that you’re most likely to ignore. It then moves those messages to a folder called Clutter, where you can review them later.
Clutter isn't a spam filter, oh no, it comes after spam and junk filtering, and after any custom email rules.
If emails end up in Clutter, there's a chance they might not be seen for a while or missed completely! Nicht good!
We work very hard to ensure our email notifications get delivered, opened and interacted with so that there's less of a chance they end up in Clutter.
We also try to ensure that our notification emails don't share traits with emails that people might already be ignoring, lest we be tarred with the same cluttery brush!
If you want to fill your boots with a bit more clutter info, including how to turn it off (wink, cough, wink), then check out the following link:
It's [...maybe...] worth saying that Clutter is changing.....it's evolving in to something called Focused Inbox. Focused Inbox is a little bit more like the GMail approach of classifying emails in to categories like "Social" or "Promotions", without creating a big black box and reducing visibility.