Piler (mailpiler) review covering the open-source email archiving tool, Enterprise edition features, pricing, pros and cons, and top alternatives.
Category
Security
Pricing
Open Source with paid Enterprise tier, from Free (Open Source Edition); Enterprise from roughly 400 euros for the first year
Verified
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Last updated
July 18, 2026
Open SourceSelf-Hosted
Overview
Piler, published as mailpiler, is an open-source email archiving system that captures and indexes email traffic so organizations can search, retain, and produce historical email records for compliance and legal purposes.
It is available as a free, self-hosted Open Source Edition, and as a paid Enterprise Edition sold separately through mailpiler.com that adds AI-powered search, security, and professional support for organizations with stricter compliance requirements.
Key Features
The open-source core provides full-text search across archived email and attachments, tamper-evident storage, retention policy enforcement, and scalable indexing designed to handle archives of millions of messages.
The Enterprise Edition adds natural-language AI search, built-in PII detection, machine-learning-based phishing detection, data loss prevention policy support, and encrypted storage with digital fingerprinting to verify message integrity for audits and legal discovery.
Pricing
The Open Source Edition of Piler is completely free, with community support available through GitHub and forums, making it accessible to any organization willing to self-host and self-manage the archive.
The Enterprise Edition is licensed commercially, with a base license reported around 400 to 2,000 euros for the first year covering one server, renewals from roughly 150 euros per year, and a 30-day free trial that includes all Enterprise features.
Key Features
Full-text search and filtering — Search archived email content and attachments quickly across large mail volumes.
Tamper-evident archiving — Stores messages in a way designed to prove they have not been altered after archiving.
Retention policy enforcement — Configurable rules to retain email records for required compliance periods.
Scalable indexing and storage — Optimized to handle archives containing millions of emails efficiently.
AI-powered natural language search (Enterprise) — Allows plain-English queries that are translated into precise archive searches.
PII and phishing detection (Enterprise) — Built-in detection of personally identifiable information and machine-learning-based phishing identification.
DLP policy support (Enterprise) — Data loss prevention policies to flag or restrict sensitive content in the archive.
Encrypted storage with digital fingerprinting (Enterprise) — Encrypts archived messages and verifies integrity with digital fingerprints.
Pros & Cons
Pros
Genuinely free and open-source core product, unusual for email archiving software
Scales to large mail volumes with efficient search and indexing
Enterprise edition adds meaningful compliance features like PII and phishing detection
30-day free trial available for Enterprise features before committing
Clear upgrade path from self-hosted open source to supported Enterprise edition
Cons
Open Source Edition has only community support, no guaranteed response time
Enterprise pricing and licensing model can be complex to evaluate for smaller organizations
Requires self-hosting infrastructure and mail server integration knowledge
AI-powered search and advanced security features are Enterprise-only
Less brand recognition than large commercial archiving vendors like Mimecast or Proofpoint
Pricing
Open Source Edition Free N/A
Enterprise Edition From ~400 EUR first year (renewals from ~150 EUR/year) Annual license
Frequently Asked Questions
What is mailpiler (Piler) used for
Piler is used for archiving incoming and outgoing email so organizations can search, retain, and retrieve records for compliance and legal e-discovery purposes.
Is Piler free
The Open Source Edition of Piler is free to self-host; a paid Enterprise Edition adds AI search, advanced security features, and professional support.
Who maintains the Piler project
Piler is maintained primarily by a developer known as jsuto, with the core source code publicly available on GitHub.
What does the Enterprise Edition of Piler add
The Enterprise Edition adds AI-powered natural-language search, PII detection, phishing detection, DLP policy support, and encrypted storage with digital fingerprinting.
How much does Piler Enterprise cost
Piler Enterprise licensing has been reported to start around 400 to 2,000 euros for the first year with renewals from about 150 euros per year, plus a 30-day free trial.
What are alternatives to Piler for email archiving
Common alternatives include Mimecast, Barracuda Message Archiver, Proofpoint Archiving, and Global Relay, along with other self-hosted archiving tools.