Hide the "Validate-MailFlowThroughFrontDoor" command for Exchange Server 2019 and 2016 Content provided by Microsoft Applies to: Exchange Server 2019Exchange Server 2016 Select Product Version All Products Summary This update makes the Validate-MailFlowThroughFrontDoor command hidden in Microsoft Exchange Server 2019 and Exchange Server 2016. It is for internal use only. How to get this update To get this update, install one of the following updates:The Cumulative Update 3 for Exchange Server 2019 or a later cumulative update for Exchange Server 2019.The Cumulative Update 14 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016. References Learn about the terminology that Microsoft uses to describe software updates. Last Updated: 17 Sep 2019 Was this information helpful? Yes No Tell us what we can do to improve the article Submit Thanks! Your feedback will help us improve the support experience.