iRedMail

iRedMail is a turnkey, open‑source mail stack that bundles a curated set of industry‑standard components—Postfix, Dovecot, Roundcube (or SOGo), SpamAssassin, ClamAV, and a MySQL/PostgreSQL backend—into a single cohesive platform. From a developer’s perspective, the system acts as an orchestrated micro‑service cluster that handles SMTP submission and relay, IMAP/POP3 retrieval, webmail rendering, and administrative APIs. The stack is hardened by default: all traffic is TLS‑only for SMTP/IMAP/POP3, and authentication hashes are stored with SSHA512 or BCRYPT. The architecture exposes a REST‑like API through the iRedAdmin web console, allowing programmatic user provisioning, domain management, and policy configuration without manual edits to /etc/postfix or Dovecot config files.

Architecture & Technical Stack

• Core Mail Transfer – Postfix as the MTA, configured with sender‑policy checks and SPF/DKIM/DMARC enforcement.
• Message Retrieval – Dovecot handles IMAP/POP3, with optional Sieve filtering exposed via a dedicated dovecot-sieve service.
• Web Interface – Roundcube (or optional SOGo) provides a modern, responsive webmail UI, backed by a lightweight PHP/NGINX stack.
• Database Layer – MySQL or PostgreSQL stores user accounts, domain metadata, and policy tables; the schema is generated during installation.
• Security & Spam – SpamAssassin, ClamAV, and Postgrey run as separate daemons, integrated into the MTA pipeline.
• Administration – iRedAdmin (PHP) offers a web console with role‑based access; it also publishes JSON endpoints for automation.

The stack is built on POSIX shells and Python scripts that orchestrate the configuration of each component, ensuring idempotency across upgrades. All components run as systemd services with clear dependencies, making the deployment predictable on any supported Linux/BSD distribution.

Core Capabilities & APIs

• User & Domain Management – Create, delete, and modify mailbox users via API calls (/api/v1/users).
• Policy Configuration – Expose per‑domain SPF/DKIM settings, quota limits, and mailbox size controls through the same API.
• Sieve Integration – Programmatic Sieve rule installation via dovecot-sieve CLI or REST endpoint, enabling automated mailbox filtering.
• Webhooks – iRedMail can trigger external scripts on events such as user creation or mailbox quota breach.
• SMTP/IMAP Hooks – Postfix header_checks and Dovecot userdb hooks allow custom authentication or message rewriting.

These APIs are documented in the official docs and can be consumed by CI/CD pipelines, configuration management tools (Ansible, Chef), or custom monitoring dashboards.

Deployment & Infrastructure

iRedMail is designed for self‑hosting on a single physical or virtual machine, but it scales horizontally with minimal friction. Each component can be containerized; the official iredmail/dockerized repository provides a ready‑to‑run Docker Compose stack that mirrors the native installation. For larger deployments, you can split services across multiple hosts: Postfix on a relay node, Dovecot and webmail behind a load balancer, and the database in a replicated cluster. The platform supports cloud‑native deployments on Kubernetes via Helm charts (community maintained), enabling rolling upgrades and pod autoscaling.

Integration & Extensibility

The modular nature of iRedMail makes it a drop‑in replacement for legacy mail servers. Developers can replace the webmail front end with their own SPA, or swap Postfix for Exim if needed—only the configuration scripts need adjustment. The plugin system allows adding custom authentication backends (OAuth2, LDAP) or extending the admin console with new modules. The open‑source license (GPL v3) guarantees that any modifications can be shared or kept private, depending on the organization’s policy.

Developer Experience

The installation guide is a single script that validates dependencies, installs packages from EPEL or the official iRedMail repo, and generates secure configuration files. Documentation is comprehensive: installation, migration, API reference, and troubleshooting sections are all interlinked. The community forum is active, with contributors frequently patching bugs or adding features. Paid support options are available for enterprises that require SLAs, but the core project remains free and fully auditable.

Use Cases

1. Enterprise Private Mail – Companies needing full control over email traffic and compliance can deploy iRedMail on-premises, leveraging the built‑in encryption and audit logs.
2. Educational Institutions – Universities can host domain‑based mail for staff and students, integrating with LDAP/Active Directory for single sign‑on.
3. Service Providers – ISPs or hosting firms can offer managed mail services by automating user provisioning via the API and scaling the stack with Docker or Kubernetes.
4. Security‑Focused Startups – Teams that require end‑to‑end encryption and custom filtering can script Sieve rules and integrate with external threat intelligence feeds.

Advantages

• Performance – Postfix and Dovecot are proven high‑throughput mail engines; the stack is tuned for low latency.
• Flexibility – All components are open‑source, allowing developers to replace or extend any part of the pipeline.
• Security by Default – TLS enforcement,