Clutter for Office 365 is an inbuilt tool for sorting emails. Clutter will determine which emails are a low priority and automatically move them to a folder named ‘clutter’ in your mailbox. Clutter will analyse your habits and based on your previous behaviour and will ‘tidy’ up your emails you are likely to ignore. Here is how you can disable clutter for Office 365.
With the following powershell commands you can turn this off for all users:
$UserCredential = Get-Credential
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Get-Mailbox | Set-Clutter -Enable $false