Step-by-Step Setup for Elgr Anti-Spam: From Installation to Tuning
1. Preparation
- System requirements: Ensure your server/host meets the OS, CPU, RAM, disk, and network requirements (assume a modern Linux distribution, 2+ CPU cores, 4+ GB RAM, and 10+ GB free disk unless vendor docs specify otherwise).
- Backups: Snapshot your mail server and configuration before changes.
- Access: Have root or sudo access and SSH ready.
2. Installation
- Obtain package: Download the Elgr Anti-Spam package or add the vendor repository per their install instructions.
- Install dependencies: Install required packages (mail transfer agent hooks, Python/Perl runtime, database client libraries, etc.).
- Install software: Use the vendor-provided installer or package manager (e.g., apt, yum) to install Elgr Anti-Spam.
- Verify service: Start the Elgr services and check status (systemctl status elgr-).
3. Integrate with Mail Flow
- MTA integration: Configure your MTA (Postfix, Exim, or Sendmail) to route incoming mail through Elgr — commonly via a content filter, milter, or SMTP proxy.
- Ports and firewalls: Open required ports and update firewall rules for proxy/listening ports.
- TLS: Enable TLS between MTA and Elgr if supported.
4. Initial Configuration
- Admin UI: Log into the web admin console (create admin user if prompted).
- Domain/mailbox setup: Add your domains, mail servers, and relay settings.
- Whitelist/blacklist: Import known safe senders and blocklists to reduce false positives.
- User sync: Connect to your directory (LDAP/AD) if available to sync users.
5. Detection & Policy Settings
- Spam sensitivity: Set baseline spam/ham thresholds (start conservative to avoid false positives).
- Policies: Configure actions per category (tag, quarantine, reject, deliver-with-header).
- Attachments: Define rules for dangerous attachment types and size limits.
- Greylisting/Rate limiting: Enable if supported and tune time windows and thresholds.
6. Quarantine & Notifications
- Quarantine retention: Set retention period and storage limits.
- User access: Enable user quarantine portals or daily digest notifications.
- Admin notifications: Configure alerts for quarantine growth, service errors, and updates.
7. Tuning and Testing
- Monitor logs: Watch Elgr and MTA logs for delivery errors and classification evidence.
- Test mailflows: Send varied test messages (clean, spam, phishing, with attachments) to observe handling.
- Adjust thresholds: Lower sensitivity if many false positives; raise if spam gets through.
- Feedback loop: Enable user-reported spam/ham reporting and feed that back into the system.
- Reputation sources: Enable/disable external blocklists and reputation feeds based on false-positive impact.
8. Performance & Scaling
- Resource monitoring: Track CPU, memory, I/O; increase resources if latency grows.
- High availability: Deploy multiple Elgr nodes with load balancing or clustering for failover.
- Database tuning: Optimize DB settings and retention policies.
9. Maintenance
- Updates: Apply software and signatures regularly (automate if possible).
- Signature feeds: Keep spam signatures and reputation data up to date.
- Periodic review: Review quarantine, policies, and whitelist/blacklist monthly.
10. Troubleshooting Checklist
- Service down — check systemctl, logs, disk space.
- Mail delayed — inspect MTA queue and Elgr processing latency.
- False positives — review quarantine, add safe senders, adjust thresholds.
- Missed spam — review logs, enable additional reputation feeds, tighten rules.
If you want, I can produce exact CLI commands and example Postfix configuration snippets for a typical Linux setup.
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