Darktrace - Using self-learning AI, Darktrace transforms the ability of organizations to defend themselves in the face of rising cyber threats
Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
ExtraHop - ExtraHop is a stream analytics platform that provides the fastest, richest, most complete visibility into all activity in IT infrastructure.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
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.
Proxmox Mail Gateway - Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.