G Suite

   formerly Google Apps for Work and Google Apps for Your Domain is a brand of cloud computing, productivity and collaboration tools, software and products developed by Google.

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.

No Cache Content

   Forces caches to submit the request to the origin server for validation before releasing a cached copy.

NO Store HTTP Cache-Control

   The cache should not store anything about the client request or server response.