Office 365 Clutter stuff

What is Clutter ?
Clutter is an email filtering option available to Office 365 customers.  It is similar to an anti-spam filter as it moves less important email (based on your reading habits) into a 'Clutter' folder where they can be ignored or reviewed later.  Most of the mail going into the folder should be bulk mail (advertisements) and messages from mailing lists.  However, you will want to periodically check the Clutter folder as it may move legitimate email into this folder.

When is Clutter applied ? 
Messages are handled in the following way in Exchange online:

1. Message are scanned by Exchange online protection (EOP)
2. Message rules in the tennant/Exchange online
3. If the mail gets to the user mailbox
1. Junk e-mail filtering
2. Mailbox rules (if a message is handled by a rule clutter processing will not happen)
3. Clutter processing

Disable Clutter (as a user)
It's possible to disable Clutter per user. Just follow the guide below:

1. Log into OWA
2. Click on the Gear > Options > Automatic Processing > Clutter
3. Select Don't separate items identified as Clutter 
4. Click Save.

Disable Clutter for the company (using a transport rule) ?
Create a new transport rule and use the following header/vaule to bypass Clutter for that e-mail:

• HeaderName X-MS-Exchange-Organization-BypassClutter
• Value true

Links

• Clutter Threshold and Probability Outlook form
• Use Clutter to sort low priority messages in Outlook 2016 for Windows
• Use a transport rule so messages can bypass Clutter