Email Hosting Providers

Amazon SESAmazon SES

Amazon SES Usage Statistics · Download List of All Websites using Amazon SES

Amazon Simple Email Service (Amazon SES) is a scalable, bulk, transactional email-sending service for businesses and developers.

Transactional Email

MasterBaseMasterBase

MasterBase Usage Statistics · Download List of All Websites using MasterBase

MasterBase tries to help you improve email marketing campaign performance, boost deliverability and lower costs.

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.