Barracuda Email Security Service VS Hornetsecurity

Trustwave Secure Email Gateway - Trustwave Secure Email Gateway helps protect your email environment against modern threats such as malware, ransomware and phishing, and helps prevent loss of sensitive corporate data.

Proofpoint - Proofpoint provides cloud-based email security, e-discovery and compliance solutions for companies to protect sensitive business data.

Mimecast Secure Email Gateway - Prevent targeted email-borne attacks with Mimecast Secure Email Gateway for cloud-based anti-virus and anti-spam protection.

Mimecast Gateway - Mimecast Gateway is a SaaS-based email security solution that uses sophisticated, multi-layered detection engines and intelligence to protect email data and employees from malware, spam, advanced threats and zero-day attacks.

Appriver - AppRiver is an email and web security company, develops SaaS-based anti-spam, hosted exchange, email encryption and web protection solutions.

dmarcian - Safeguard your email from abuse