Email Hosting Providers

SendinBlueSendinBlue

SendinBlue Usage Statistics · Download List of All Websites using SendinBlue

Marketing campaigns, Transactional Emails, and SMS messages all in one platform.

Marketing Platform

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

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