First, connect to your tenant Get-HostedContentFilterPolicy |fl We need to manage the AllowedSenderDomains field. Issue this command to see the situation … Get-HostedContentFilterPolicy |fl AllowedSenderDomains If you want to expant it do this: Get-HostedContentFilterPolicy | select -ExpandProperty AllowedSenderDomains To filter it and show only the domains list use this command: Get-HostedContentFilterPolicy | select -ExpandProperty AllowedSenderDomains …