WiseStamp - WiseStamp allows you to easily create and implement slick and unique email signatures for your business.
Nessus - Nessus Professional is a security platform designed for businesses who want to protect the security of themselves, their clients, and their customers.
MySignature - MySignature is FREE Email Signature Generator that helps to create Professional Signatures for major email clients such as Outlook, Gmail...
Tenable.io - Tenable.io Cyber Exposure platform helps to protect any asset on any computing platform and eliminate blind spots.
Sigstr - Email signature marketing
AlienVault USM (from AT&T Cybersecurity) - AlienVault USM Anywhere delivers powerful threat detection, incident response, and compliance management for cloud, on-premises, and hybrid environments.