@wrx7m said in Exchange 2016 - NDR: @scottalanmiller said in Exchange 2016 - NDR: @Natchos said in Exchange 2016 - NDR: @JasGot Awesome, thanks for the input. I'll look into SPF. SPF is considered a requirement these days. And DKIM is heavily recommended. People are starting to come around. I have been using DKIM for a few years for all services sending email outside our org. With O365, SPF and DKIM are part of the setup. Same with Zoho.