Workplace by FacebookWorkplace by Facebook

Workplace by Facebook Usage Statistics · Download List of All Websites using Workplace by Facebook

Group discussion, a personalised News Feed, and voice and video calling from Facebook.

Email Hosting Providers

SPFSPF

SPF Usage Statistics · Download List of All Websites using SPF

The Sender Policy Framework is an open standard specifying a technical method to prevent sender address forgery.

Standard

Google Apps for BusinessGoogle Apps for Business

Google Apps for Business Usage Statistics · Download List of All Websites using Google Apps for Business

Web-based email, calendar, and documents for teams. Renamed to Google Apps for Work, but now known as G Suite From Google Cloud.

Business Email Hosting

Operating Systems and Servers
Verified CDN

Amazon S3 CDNAmazon S3 CDN

Amazon S3 CDN Usage Statistics · Download List of All Websites using Amazon S3 CDN

Amazon S3 is storage for the Internet. It is designed to make web-scale computing easier for developers.