Piler Email Archiving: Tool for Long-Term Email Retention
Piler is an open-source email archiving solution built to help organizations keep mail communication secure, searchable, and compliant. It captures and stores messages in a tamper-proof archive, indexing them so administrators and compliance officers can quickly retrieve what they need. Unlike heavy enterprise suites, Piler focuses on being efficient and transparent, with a clean web interface and integrations that fit into existing mail systems.
Core Characteristics
| Aspect | Details |
| Platform | Linux (server-side), web-based access |
| Main purpose | Secure archiving and search of emails |
| Supported input | Works with Postfix, Exim, Microsoft Exchange (via SMTP journaling) |
| Storage | Compressed, encrypted archive, optimized for long-term retention |
| Access | Web UI for users/admins; role-based permissions |
| Features | Full-text search, deduplication, legal hold, retention policies |
| Security | TLS, S/MIME, encryption at rest, audit logs |
| Licensing | Open source (GPL) |
| Target users | Enterprises, schools, government, ISPs needing regulatory compliance |
How It’s Used in Practice
Organizations deploy Piler when they need a reliable way to keep complete records of email correspondence. For compliance-driven industries — finance, healthcare, public sector — it ensures that every message can be recovered quickly in case of an audit. Service providers integrate it with Postfix or Exchange to give customers compliant archiving as part of hosted mail services. Even smaller companies use it to offload old messages into an archive, keeping primary mail servers lean.
Deployment Notes
– Runs on Linux, usually alongside an MTA such as Postfix or Exim.
– Messages are captured via journaling and fed into the archive server.
– Storage is compressed and indexed for efficient searching.
– Provides a web interface for end users, administrators, and compliance officers.
– Retention rules and legal hold can be applied at policy level.
Typical Scenarios
– A bank uses Piler to keep seven years of customer email for regulatory checks.
– A school district archives all staff mail in a centralized system for legal protection.
– A hosting provider bundles Piler-based archiving into its business email offering.
Limitations
Piler is focused solely on email archiving. It does not replace a full backup system and does not provide productivity features like calendars or tasks. Integration is simpler with Linux-based MTAs than with proprietary platforms. For very large environments, scaling requires careful planning of storage and indexing resources.
Quick Comparison
| Tool | Distinctive Strength | Best Fit |
| Piler | Open-source, efficient archiving | Compliance-focused orgs, mail hosting |
| MailArchiva | Cross-platform, broad MTA support | Mixed environments needing flexibility |
| Barracuda Archiver | Commercial, turnkey appliance | Enterprises wanting ready-made solution |
| Microsoft 365 Compliance | Built-in cloud archiving | Organizations already on Microsoft 365 |


