Rspamd - Rspamd is an advanced spam filtering system that allows evaluation of messages by a number of rules...
MX Save - MXSAVE is an email disaster recovery service that works seamlessly with on-premise or hosted anti-spam solutions.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
Happy Moose - Happy Moose is a super-efficient cloud anti-SPAM solution for organizations. It stops up to 99.
Proxmox Mail Gateway - Protect mail server against spam, viruses and malware with Proxmox Mail Gateway security for businesses, government, education and non-profit organizations.
Hornetsecurity - Hornetsecurity offers you comprehensive, integrated managed e-mail security services.