wildduck
Scalable no-SPOF IMAP/POP3 mail server for hosting providers and operators
WildDuck provides a scalable IMAP/POP3 mail server designed to avoid a single point of failure. It stores all data, including email, in a sharded and replicated MongoDB backend. Its product design generally follows Gmail, and a separately documented HTTP API is available. It also supports labels and can place attachments in object storage according to a configurable minimum object size. WildDuck is part of the Zone Mail Suite, a collection of programs and modules for running a modern email server.
It is intended for operators and organizations that need a scalable IMAP/POP3 mail backend without a single point of failure. The materials do not narrow the audience further or provide performance or scale benchmarks.
No specific paid product is named as the product WildDuck replaces. As a result, the available research does not support a direct feature, pricing, or migration comparison against a commercial mail server. It establishes the core capabilities of a mail backend—IMAP/POP3, distributed storage, labels, attachment handling, and an HTTP API—but does not document where WildDuck falls short of any named paid alternative. It also does not cover commercial support options, supported operating systems, runtime requirements, or detailed Docker Compose setup.
Key features
- No-SPOF IMAP/POP3 mail server
- Sharded and replicated MongoDB storage
- Gmail-like product design philosophy
- Separately documented HTTP API
- Label support
- Configurable object storage for attachments
vs Unknown
The research does not name a paid product that WildDuck replaces. WildDuck’s documented abilities include IMAP/POP3 service, distributed MongoDB storage, labels, object storage for attachments, and an HTTP API, but no direct comparison with a commercial product is available. It fits operators and organizations seeking a scalable mail backend without a single point of failure. The materials do not establish which users should choose a paid alternative or what WildDuck lacks relative to one.
Install
What's new in v1.55.3
## [1.55.3](https://github.com/zone-eu/wildduck/compare/v1.55.2...v1.55.3) (2026-11-02) ### Bug Fixes * **attachments-s3-gridfs-migration:** ZMS-123: Add S3 -> GridFS migration script ([#1244](https://github.com/zone-eu/wildduck/issues/1244)) ([2648fa1](https://github.com/zone-eu/wildduck/commit/2648fa15d380f67d172b21d7ee3d1d10e818cb60)) * **attachments:** Only store attachments above minObjectSize in Object store…
