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What is Mailborder?

Mailborder V6 is an enterprise-grade email security gateway designed to protect organizations from spam, viruses, malware, phishing attacks, and other email-based threats. It sits between the Internet and your mail server, scanning and filtering all inbound and outbound email traffic.

Overview

Mailborder acts as a protective barrier for your email infrastructure by:

  • Scanning every email for spam, viruses, and malware
  • Filtering unwanted or malicious messages before they reach users
  • Enforcing organizational email policies and compliance requirements
  • Quarantining suspicious emails for review
  • Blocking known malicious senders and content
  • Validating sender authenticity through SPF, DKIM, and DMARC
  • Logging all email activity for auditing and compliance

How It Works

Internet → Mailborder V6 → Your Mail Server → User Mailboxes
            ↓
        Spam Filter
        Virus Scanner
        Policy Engine
        Quarantine

When email arrives, Mailborder:

  1. Receives the email from the sending server
  2. Analyzes the sender, content, and attachments
  3. Scores the email based on spam indicators
  4. Scans for viruses and malware
  5. Checks against policy rules and reputation databases
  6. Makes a decision - deliver, quarantine, or reject
  7. Logs the transaction for auditing

Clean email is delivered to your mail server. Suspicious email is quarantined for administrator or user review. Malicious email is blocked entirely.

Key Capabilities

Multi-Layered Protection

Mailborder employs defense-in-depth with multiple scanning engines:

  • Rspamd - Advanced spam detection with machine learning
  • ClamAV - Comprehensive antivirus and malware scanning
  • RBL Checks - Real-time blacklist queries
  • SPF/DKIM/DMARC - Sender authentication validation
  • Content Analysis - Suspicious patterns and keywords
  • Attachment Filtering - Block dangerous file types
  • GeoIP Filtering - Country-based sender restrictions

Flexible Deployment

Mailborder adapts to your infrastructure:

  • Standalone Mode - All-in-one appliance for single sites
  • Cluster Mode - Distributed processing for high-volume environments
  • High Availability - Redundant configurations for mission-critical deployments
  • Virtual or Physical - Deploy on bare metal, VMs, or cloud instances

Centralized Management

The web-based administration interface provides:

  • Dashboard - Real-time statistics and system health
  • User Management - Create and manage administrator accounts
  • Policy Configuration - Define filtering rules and actions
  • Quarantine Management - Review and release held messages
  • Reporting - Comprehensive email activity reports
  • Log Viewer - Search and analyze email transactions

Enterprise Features

  • Multi-Factor Authentication - TOTP, passkey/WebAuthn support
  • Role-Based Access Control - Granular administrator permissions
  • API Access - Programmatic integration with external systems
  • Multi-Language Support - 56 language translations
  • Custom Branding - White-label the interface
  • LDAP/AD Integration - Synchronize with directory services

Architecture Highlights

Mailborder V6 is built on a modern, secure architecture:

Service-Based Design

Multiple specialized daemons work together:

  • mb-milter - Postfix policy integration
  • mb-eval - Policy evaluation engine
  • mb-filter - Spam and virus scanning
  • mb-virtuoso - Queue management and orchestration
  • mb-scribe - Logging and statistics
  • mb-cron - Scheduled maintenance tasks
  • mb-rpcd - Web interface backend
  • mb-guardian - Service health monitoring

Each service is isolated, secured, and independently managed through SystemD.

Security First

Mailborder implements multiple security layers:

  • Encrypted Code Execution - Core logic runs from encrypted binaries
  • Unix Socket Communication - Internal services use local sockets, not network ports
  • Process Isolation - Each request runs in an isolated fork
  • Privilege Separation - Services run as non-root users
  • SystemD Hardening - Resource limits, capability restrictions
  • Session Security - Fingerprinting, CSRF protection, secure cookies

Performance Optimized

  • In-Memory Caching - Redis for fast lookups
  • Connection Pooling - Persistent database connections
  • Parallel Processing - Multi-process scanning
  • Queue Management - Efficient message handling
  • Resource Limits - Prevent runaway processes

Use Cases

Mailborder is deployed across diverse industries:

Small to Medium Business

  • Protect 50-5,000 mailboxes
  • Reduce spam to near zero
  • Block viruses before they reach users
  • Simple web-based management
  • Affordable licensing

Enterprise

  • Scale to 50,000+ mailboxes
  • Cluster multiple nodes for redundancy
  • Integrate with existing infrastructure
  • Customize policies per department
  • Detailed compliance reporting

Service Providers

  • Multi-tenant white-label deployments
  • API integration for provisioning
  • Usage tracking and billing data
  • High-volume processing
  • 24/7 reliability requirements

Regulated Industries

  • Healthcare (HIPAA compliance)
  • Finance (SOX, PCI-DSS)
  • Government (FISMA, FedRAMP)
  • Legal (attorney-client privilege)
  • Air-gapped secure environments

Why Choose Mailborder?

Proven Technology

  • Built on battle-tested open source components
  • Postfix, Rspamd, ClamAV, MariaDB, Redis
  • Refined through years of production deployments
  • Active development and security updates

Comprehensive Protection

  • Multi-engine scanning catches what others miss
  • Continuously updated threat intelligence
  • Machine learning adapts to evolving threats
  • Zero-day protection through heuristic analysis

Easy to Manage

  • Intuitive web interface
  • Minimal command-line requirements
  • Automatic updates and maintenance
  • Clear documentation and support

Flexible and Scalable

  • Start small, grow as needed
  • Add nodes to increase capacity
  • Customize policies to your needs
  • Integrate with existing systems

Secure by Design

  • Nuclear-facility-level security architecture
  • Encrypted code prevents tampering
  • Multiple isolation boundaries
  • Regular security audits

What Mailborder Is NOT

To set appropriate expectations:

  • Not a Mail Server - Mailborder filters email but doesn't store mailboxes. You still need Exchange, Zimbra, Postfix/Dovecot, or similar.
  • Not a Backup Solution - While email is temporarily stored during processing, Mailborder is not a long-term email archive.
  • Not a Compliance Archive - For regulatory email retention, use dedicated archiving solutions alongside Mailborder.
  • Not a Collaboration Platform - Mailborder focuses on security, not calendaring, contacts, or document sharing.

Next Steps

Now that you understand what Mailborder is, explore:

Or jump straight to Installation if you're ready to get started.