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

Web Hosting Providers
Web Servers

nginxnginx

nginx Usage Statistics · Download List of All Websites using nginx

nginx [engine x] is a HTTP server and mail proxy server written by Igor Sysoev.