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.

Cloudflare

   Cloudflare, Inc. is an American web infrastructure and website security company, providing content delivery network services, DDoS mitigation, Internet security, and distributed domain name server services

Vary Header Accept-Encoding

   The Accept-Encoding request HTTP header advertises which content encoding, usually a compression algorithm, the client is able to understand. Using content negotiation, the server selects one of the proposals, uses it and informs the client of its choice with the Content-Encoding response header.

Viewport - initial-scale

   The viewport is the user`s visible area of a web page. The viewport varies with the device, and will be smaller on a mobile phone than on a computer screen. Before tablets and mobile phones, web pages were designed only for computer screens, and it was common for web pages to have a static design and a fixed size.

Viewport - Mobile compatible

   The viewport is the user`s visible area of a web page. The viewport varies with the device, and will be smaller on a mobile phone than on a computer screen. Before tablets and mobile phones, web pages were designed only for computer screens, and it was common for web pages to have a static design and a fixed size.

Viewport - Width

   The viewport is the user`s visible area of a web page. The viewport varies with the device, and will be smaller on a mobile phone than on a computer screen. Before tablets and mobile phones, web pages were designed only for computer screens, and it was common for web pages to have a static design and a fixed size.

Chunked transfer encoding

   Chunked transfer encoding is a streaming data transfer mechanism available in version 1.1 of the Hypertext Transfer Protocol (HTTP). In chunked transfer encoding, the data stream is divided into a series of non-overlapping "chunks"