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

Unified LayerUnified Layer

Unified Layer Usage Statistics · Download List of All Websites using Unified Layer

Unified Layer is a brand owned by EIG, an owner of over 50 hosting providers.

US hosting

Operating Systems and Servers

OpenSSLOpenSSL

OpenSSL Usage Statistics · Download List of All Websites using OpenSSL

The OpenSSL Project is a collaborative effort to develop a robust, commercial-grade, full-featured, and Open Source toolkit implementing the Secure Sockets Layer (SSL v2/v3) and Transport Layer Security (TLS v1) protocols as well as a full-strength general purpose cryptography library.