Email Hosting Providers

DMARCDMARC

DMARC Usage Statistics · Download List of All Websites using DMARC

A technical specification created by a group of organizations that want to help reduce the potential for email-based abuse

Standard

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

Operating Systems and Servers

UnixUnix

Unix Usage Statistics · Download List of All Websites using Unix

A *nix based operating system (undisclosed).