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.

Mandrill

   Mandrill is a scalable and affordable email infrastructure service. Mandrill is a paid Mailchimp add-on.

Zendesk

   Zendesk Inc. is a customer service software company headquartered in San Francisco, California, USA. It is listed on the New York Stock Exchange with the symbol ZEN and is a constituent of the Russell 2000 Index

X-Frame-Options Header

   The X-Frame-Options HTTP response header can be used to indicate whether or not a browser should be allowed to render a page in a <frame>, <iframe>, <embed> or <object>. Sites can use this to avoid clickjacking attacks, by ensuring that their content is not embedded into other sites.