SPF

   The Sender Policy Framework (SPF) is an email-authentication technique which is used to prevent spammers from sending messages on behalf of your domain. With SPF an organisation can publish authorized mail servers.

Microsoft Office 365

   Microsoft Office 365 is a Software as a Service (SaaS) solution that includes Microsoft Office and other services, such as email and collaboration, from Microsoft’s cloud server. Microsoft Office 365 provides desktop functionalities and is available by subscription.

Google Hosted Libraries

   The Google Hosted Libraries is a stable, reliable, high-speed, globally available content distribution network for the most popular, open-source JavaScript libraries.

jquery 3.1.1

   JavaScript library for DOM operations

Apache

   The Apache HTTP Server, colloquially called Apache, is free and open-source cross-platform web server software, released under the terms of Apache License 2.0. Apache is developed and maintained by an open community of developers under the auspices of the Apache Software Foundation.

Plesk

   Plesk is a commercial web hosting platform with a control panel that allows a server administrator to set up new websites, reseller accounts, e-mail accounts

Server partial requests support

   The Accept-Ranges response HTTP header is a marker used by the server to advertise its support of partial requests. The value of this field indicates the unit that can be used to define a range.