Cryoserver Email Archive

Best Self Hosted Alternatives to Cryoserver Email Archive

A curated collection of the 5 best self hosted alternatives to Cryoserver Email Archive.

Cloud email-archiving service that captures, retains and indexes email for compliance, eDiscovery and long-term preservation. Provides retention policies, supervised review, audit trails, search and export/restore capabilities.

Alternatives List

#1
Open Archiver

Open Archiver

Self-hosted email archiving platform for ingesting, storing, indexing and searching emails from Gmail, Microsoft 365, IMAP, PST and more.

Open Archiver screenshot

Open Archiver is an open-source platform designed to ingest, store, index and search email archives for compliance and e-discovery. It supports bulk imports and continuous synchronization from major providers and preserves emails in standard .eml format for tamper-evident records. (github.com)

Key Features

  • Universal ingestion: bulk import and continuous sync from IMAP, Google Workspace (Gmail), Microsoft 365, PST, mbox and zipped .eml files. (github.com)
  • Secure, deduplicated storage: stores original emails in .eml format with deduplication, compression and at-rest encryption (supports local filesystem and S3-compatible backends). (github.com)
  • Full-text indexing and search: indexes message text and common attachment types for high-performance search and e-discovery workflows. (github.com)
  • Thread discovery and context: groups related messages into conversation threads to present context during review. (github.com)
  • Integrity and auditing: computes file hashes and records integrity reports; maintains an immutable audit trail of system activities and accesses. (github.com)
  • Pluggable backends and async processing: uses job queues for ingestion and supports S3-compatible object storage for scalable deployments. (github.com)

Use Cases

  • Regulatory compliance and legal discovery: preserve corporate email archives and provide searchable records for audits and litigation. (github.com)
  • Long-term retention and corporate recordkeeping: centralized, tamper-evident storage of organizational communication history. (github.com)
  • Migration, forensic analysis and audits: bulk-import PST/mbox files and perform full-text searches across messages and attachments. (github.com)

Limitations and Considerations

  • Legal-hold controls are noted as "TBD" in the project documentation; organizations requiring built-in, mature legal-hold features should evaluate current status before relying on it for litigation holds. (github.com)

Open Archiver is positioned as a modern, open-source tool for teams that need vendor-neutral email retention and searchable archives. A live demo and full installation instructions are provided by the project for evaluation and deployment. (github.com)

1.6kstars
65forks
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#2
Mail-Archiver

Mail-Archiver

Self-hosted email archiving system for syncing IMAP and Microsoft 365 mailboxes, indexing content and attachments, and exporting or restoring mailboxes with auditing and retention.

Mail-Archiver is a web application for archiving emails from multiple accounts into a searchable database. It synchronizes mailbox folders and attachments, supports exports and restores, and provides a dashboard for monitoring usage and activity.

Key Features

  • Multi-account archiving with scheduled synchronization of folders and attachments
  • Supports IMAP accounts, Microsoft 365 via Microsoft Graph API, and import-only migration accounts
  • Advanced search and filtering across archived emails, with message preview and attachment lists
  • Export full accounts to MBOX or zipped EML archives, plus batch/individual email export
  • Import MBOX and EML (ZIP with folder structure) for mailbox migration and consolidation
  • Restore selected emails or entire mailboxes back to destination mailboxes
  • Multi-user access with account-scoped permissions and detailed access/activity logging
  • Retention policies for automatic deletion from the source mailserver and separate local-archive retention
  • OpenID Connect (OIDC) support for integrating external identity providers

Use Cases

  • Centralized, searchable archive for multiple mailboxes (personal, team, or organizational)
  • Mailbox migration and consolidation using MBOX/EML import and export
  • Compliance-style retention workflows and audit-friendly access logging

Limitations and Considerations

  • Does not provide HTTPS itself and is intended to be placed behind a reverse proxy
  • Not designed for direct exposure to the public internet

Mail-Archiver is suited for operators who want a practical email archiving and migration tool with strong search, export options, and operational visibility. Its account provider support and retention features make it useful for ongoing archiving as well as one-time consolidation projects.

1.5kstars
45forks
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#3
Bichon

Bichon

Self-hosted email archiving server that syncs from IMAP, stores a local compressed archive, and provides fast full-text search via Web UI and REST API.

Bichon is a lightweight, high-performance email archiving server designed to synchronize mail from IMAP accounts into a local, searchable archive. It focuses on long-term retention, organization, and fast discovery of historical email, rather than sending or real-time communication.

Key Features

  • Continuous synchronization from one or more IMAP accounts, with unified search across accounts
  • Full-text indexing for fast search across sender, subject, body, date, size, attachments, and more
  • Built-in Web UI with multilingual support for browsing, threads, bulk cleanup, and export
  • REST API with OpenAPI documentation for programmatic access
  • OAuth2 authentication support for IMAP providers (with token refresh) alongside password login
  • Compressed storage with deduplication to reduce disk usage
  • Tagging and facets for organizing and filtering archived mail
  • Multi-user support with role-based access control (RBAC)
  • Import tooling for existing archives (EML, MBOX, PST) via CLI

Use Cases

  • Centralized archiving of multiple mailboxes for fast historical search and retrieval
  • Creating an offline, local searchable archive to reduce dependency on mailbox server retention
  • Programmatic analysis and integration of archived email via a REST API

Limitations and Considerations

  • Not an email client: it does not send email and is not intended for real-time inbox workflows
  • Browser access may require explicit CORS configuration depending on deployment and version

Bichon is well-suited for individuals or teams that need a dedicated email archive with strong search, efficient storage, and an API-first interface. Its standalone design avoids external database dependencies while still providing a modern web experience for managing archived mail.

1.1kstars
31forks
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#4
Piler

Piler

Scalable email archiving solution with tamper-evident retention, full-text search, legal hold, deduplication and access controls for compliance.

Piler screenshot

Piler is an open-source email archival application designed to capture, store, index, and retrieve large volumes of email for compliance, eDiscovery, and long-term retention. It provides a searchable, tamper-evident archive with tools for import/export, access control, and audit logging.

Key Features

  • Built-in SMTP archival server and support for ingest via MTA integration
  • Archival and retention rules with legal-hold capabilities
  • Message and attachment deduplication, compression, and optional encryption
  • Digital fingerprinting and verification for tamper-evidence
  • Full-text indexing with simple and expert search interfaces and saved searches
  • Bulk import/export and message restore functionality (EML, Maildir, mailbox formats)
  • Access control, audit logs, accounting, and search over audit records
  • Authentication integrations: AD/LDAP, IMAP/POP3, SSO, and optional two-factor authentication
  • Internationalization and customizable theming

Use Cases

  • Regulatory compliance and tamper-evident long-term email retention for legal and audit requirements
  • eDiscovery and internal investigations via fast full-text search and exportable message sets
  • Reducing primary mailbox storage costs by offloading and deduplicating archived messages

Limitations and Considerations

  • Large-scale deployments require careful planning of database, storage and indexing resources; bulk imports can be resource-intensive
  • Search and indexing performance depend on chosen storage and indexing configuration and may need tuning for very large archives

Piler is suited for organizations that need a dedicated, auditable email archive with policy-driven retention and eDiscovery tools. It is flexible in ingestion methods and authentication integrations but benefits from capacity planning for high-volume environments.

238stars
34forks
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#5
HyperKitty

HyperKitty

HyperKitty is a web interface and archiver for Mailman 3 mailing lists, providing searchable list archives, thread views, user profiles, and email interaction features.

HyperKitty screenshot

HyperKitty is a web application that provides a modern interface for browsing and searching mailing list archives, designed to work with the GNU Mailman 3 suite. It archives messages, presents conversations in a thread-oriented view, and offers user-facing tools for interacting with list content.

Key Features

  • Web-based archives with thread and conversation views
  • Full-text search across archived messages
  • Per-message pages with metadata and navigation within threads
  • User profiles and posting/activity history (when authentication is configured)
  • Integration with Mailman 3 components for archiving and list interaction
  • Administrative moderation-oriented views and archive management capabilities

Use Cases

  • Hosting searchable public or private archives for Mailman 3 mailing lists
  • Replacing traditional pipermail-style archives with a modern web UI
  • Providing community-facing mailing list history for open source projects or organizations

Limitations and Considerations

  • Primarily intended for the Mailman 3 ecosystem; it is not a standalone mailing list manager
  • Feature set and authentication/SSO capabilities depend on how it is deployed and integrated with other Mailman 3 services

HyperKitty is a strong fit for communities that rely on mailing lists and want a more accessible, searchable archive experience. When deployed alongside Mailman 3, it helps make long-running conversations easier to browse, reference, and preserve.

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Why choose an open source alternative?

  • •Data ownership: Keep your data on your own servers
  • •No vendor lock-in: Freedom to switch or modify at any time
  • •Cost savings: Reduce or eliminate subscription fees
  • •Transparency: Audit the code and know exactly what's running