How to disable Clutter folder in Office 365

This applies to shared mailboxes as well as actual user mailboxes

1. Connect to Exchange Online:
$UserCredential = Credential someone@somewhere.com
$Session = New-PSSession -ConfigurationName Microsoft.Exchange -ConnectionUri https://outlook.office365.com/powershell-liveid/ -Credential $UserCredential -Authentication Basic -AllowRedirection
Import-PSSession $Session

2. Set-Clutter -Identity user@domain.com -Enable $false