We will be upgrading the Plesk Windows server to the latest Plesk, as well as upgrading to Windows 2016 Server. This will bring about several changes, including a new WordPress Deployment Toolkit and upgrade tool, .NET CORE, Node.js services, SQL 2016 support, Let's Encrypt SSL support for Free and updated SSL certificates for all domains, and more. There will be a brief time of mail server outage during this upgrade process as it switches over servers.