Hermes SEG
Hermes SEG is a free, open-source secure email gateway and server. It delivers spam, virus, and malware protection using SpamAssassin, ClamAV, and Amavisd-new, along with full encryption in transit and at rest via SMTP TLS, S/MIME, PGP, encrypted PDF (CipherMail), and Dovecot mail-crypt. It includes email archiving and integrated mailbox hosting with quotas, aliases, shared folders, Sieve rules, vacation replies, and mobile auto-configuration. Collaboration features come through Nextcloud (webmail, file sync, calendars, contacts). Identity and access are managed with OpenLDAP and Authelia, supporting SSO and MFA (TOTP, WebAuthn, Duo). It also enforces modern authentication standards: SPF, DKIM, DMARC, and ARC.
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CacheGuard
CacheGuard-OS is a free, open-source Linux-based network security appliance OS that turns any standard x86 machine into a UTM gateway. It sits between your devices and your ISP router, becoming the checkpoint for all internet traffic — no IT team required.
Open-source since its first release, CacheGuard-OS includes: stateful firewall, web antivirus (ClamAV), URL filtering, SSL inspection, WAF (ModSecurity), VPN server (StrongSwan), web cache (Squid), QoS (IPRoute2), and WAN load balancing.
It installs on bare metal or any common hypervisor in under an hour. Configuration is handled through a web-based admin interface with no command-line expertise needed.
Built for small businesses, schools, and sysadmins who need production-grade network security on commodity hardware.
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ClearOS
Applications and an operating system come with your computer, tablet, and phone. So, why not on your server? HPE is redefining the small business server by offering ClearOS with HPE ProLiant servers. ClearOS is a simple, open, and affordable operating system with an intuitive graphical web-based user interface and an application marketplace with over 100 apps to choose from, with more being added every day. Leveraging open source software, you decide what applications you need and only pay for the applications and support you want. HPE and ClearCenter are making it easy for small, home, remote, and branch offices to have a server ready to use, out of the box, at no additional cost. HPE ProLiant integrated with ClearOS offers a simple, affordable, and secure experience. Building the IT solution that is just right for you has never been easier.
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ClamAV
ClamAV® is the open-source standard for mail gateway-scanning software. ClamAV includes a multi-threaded scanner daemon, command-line utilities for on-demand file scanning, and automatic signature updates. ClamAV supports multiple file formats and signature languages, as well as file and archive unpacking. Access to ClamAV versions that work with your operating system. ClamAV® is an open-source antivirus engine for detecting trojans, viruses, malware & other malicious threats. ClamAV® is an open-source (GPL) anti-virus engine used in a variety of situations, including email and web scanning, and endpoint security. It provides many utilities for users, including a flexible and scalable multi-threaded daemon, a command-line scanner, and an advanced tool for automatic database updates. Built-in support for various archive formats, including ZIP, RAR, Dmg, Tar, GZIP, BZIP2, OLE2, Cabinet, CHM, BinHex, SIS, and others.
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