Proxmox Mail Gateway is described as 'is the leading open-source email security solution helping you to protect your mail server against all email threats the moment they emerge'. There are eight alternatives to Proxmox Mail Gateway for a variety of platforms, including Linux, Self-Hosted solutions, SaaS, BSD and Mac. The best alternative is mailcow: dockerized, which is both free and Open Source. Other great apps like Proxmox Mail Gateway are Rspamd (Free, Open Source), SpamAssassin (Free, Open Source), MailScanner (Free, Open Source) and Scrollout F1 (Free, Open Source).
Use this program to "Unspam" your mailbox(es). The program can be integrated with the mail server to automatically filter all mail for a site. It can also be run by individual users on their own mailbox and integrates with several mail programs.
MailScanner is a open source email security system design for Linux-based email gateways. It is used at over 30,000 sites around the world, protecting top government departments, commercial corporations and educational institutions.
Xeams is a secure and powerful mail server for that includes a powerful spam filtering engine that eliminates up to 99% of junk email right out of the box. The software offers a flexible approach to email, making it a very user friendly server.
EuropeanMX blocks incoming spam and virus emails before they are reaching your network. With our outgoing filter you can secure your server's reputation. And last but not least we are offering encrypted cloud storage to archive all your emails.