30 open-source projects similar to mailu/mailu, ranked by how many features they have in common. Compare stars, activity and what each one does to find the best Mailu alternative.
Stalwart is a self-hosted email and collaboration infrastructure that provides an integrated mail server supporting SMTP, IMAP, POP3, and JMAP protocols. It functions as a comprehensive communication hub, combining email hosting with a collaboration server for shared calendars, contacts, and files. The system distinguishes itself through a distributed architecture that uses peer-to-peer cluster coordination to ensure high availability and fault tolerance. It features a built-in security suite that implements an S/MIME and OpenPGP email gateway alongside automated TLS certificate provisioning
Mox is a self-hosted email server that runs as a single compiled Go binary, handling the full lifecycle of sending and receiving email through SMTP, IMAP4rev2, and a built-in webmail application. It is designed to be operated without external dependencies or runtime plugins, with all mail services — including spam filtering, queue management, and web interfaces for administration and account management — contained in one executable. The server distinguishes itself through automated TLS certificate management via ACME, DNS-based autoconfiguration for email clients, and file-based configuration
Mail-in-a-Box is a self-hosted email server appliance that automates the deployment of SMTP, IMAP, and POP3 services on Linux. It functions as a complete suite including a DNS management server, a spam and abuse filter, and a web-based administrative control panel for managing users, aliases, and storage quotas. The project distinguishes itself through a high degree of automation for email security and authenticity. It automatically provisions and maintains SPF, DKIM, DMARC, and DNSSEC records to prevent domain spoofing, while managing the installation and rotation of TLS certificates and enf
Postal is an open-source mail delivery platform designed for self-hosted sending and receiving of email using standard mail transfer protocols. It serves as a comprehensive email infrastructure that provides full delivery tracking and management of outgoing mail streams. The system includes an SMTP server manager with a web administration interface for configuring server settings and monitoring delivery status. It distinguishes its outbound traffic management through priority-based IP rotation and assignment to help maintain sender reputation. The platform covers incoming email processing an
Mailcow-dockerized is an open-source email hosting platform that provides a complete, self-hosted infrastructure suite. It bundles message transfer, storage, and security protocols into a modular, containerized environment designed for deployment on private infrastructure. The platform distinguishes itself by integrating a centralized management interface for configuring mail domains and user accounts alongside collaborative tools like shared calendars and contact lists. It includes automated security features such as integrated spam and malware filtering gateways, as well as automated certif
This project provides a full-stack, containerized mail server platform designed for self-hosting. It functions as a complete mail transfer agent that bundles essential services—including SMTP, IMAP, and POP3—into a unified environment. By leveraging container orchestration, it enables the deployment of private email infrastructure that handles message transport, delivery, and user management within a single, manageable service. The platform distinguishes itself through deep integration with container runtimes and robust configuration flexibility. It supports granular customization via configu
Postal is an open-source email infrastructure and self-hosted delivery platform. It functions as an SMTP mail server and inbound email gateway, providing the tools necessary to send and receive email through a privately managed infrastructure. The system manages SMTP infrastructure for outgoing message delivery and provides capabilities for custom email receiving. It allows for the routing of incoming external emails to internal applications or websites for automated processing. The platform includes support for multi-tenant domain mapping, event-driven webhook notifications, and plugin-base
BillionMail is a self-hosted email infrastructure and marketing platform designed to provide full control over mail delivery, domain management, and subscriber communication. It functions as a comprehensive mail server manager that enables users to deploy and maintain private email environments, including integrated webmail interfaces for direct account access. The platform distinguishes itself by combining high-volume bulk email distribution with sophisticated deliverability tools. It supports multi-tenant infrastructure provisioning, allowing administrators to manage multiple domains and ma
This project is a community-curated directory of open-source software designed for deployment in private server environments and home labs. It serves as a comprehensive resource for discovering independent, self-hosted alternatives to mainstream cloud services, enabling users to maintain full data ownership and control over their digital infrastructure. The directory is structured through a hierarchical taxonomy that organizes a vast collection of applications into logical categories, ranging from media management and data analytics to private communication and team productivity tools. It dis
Maddy is a modular mail server that assembles a complete email system by connecting small, single-purpose modules through a declarative configuration file. Rather than a monolithic stack, it lets operators compose message processing, storage, authentication, and security enforcement from interchangeable building blocks, with each module handling a specific function like receiving SMTP connections, verifying credentials, or applying policy checks. The server distinguishes itself through its flexible authentication and security architecture. It delegates user verification to external systems in
PHPMailer is a comprehensive library for constructing and sending complex email messages within PHP applications. It provides an object-oriented framework for building MIME-compliant emails, managing attachments, and handling multi-format content such as HTML and plain-text alternatives. The library serves as a robust interface for email dispatch, supporting both individual messaging and high-performance bulk distribution through persistent connections. The project distinguishes itself through a deep focus on secure transmission and identity verification. It integrates advanced security proto
Anonaddy is an email forwarding gateway and alias manager designed to protect user identity. It functions as a mail server that routes messages from custom domains and aliases to verified destination addresses using programmable routing rules. The system provides an SMTP privacy proxy to mask the sender's real email address for outgoing messages and includes a PGP encryption tool to secure the body and headers of emails before they are forwarded. It supports custom domain email routing through DNS and MX record verification, allowing users to manage multiple identities to prevent ownership li
Mailpit is an SMTP mail testing server and web-based email inbox designed to intercept and store outgoing emails for development and integration testing without delivering them to real recipients. It functions as an SMTP mocking tool and relay gateway, allowing users to capture mail traffic and view it through a browser interface. The project distinguishes itself by providing tools for SMTP server simulation, including the ability to inject failure codes to test application resilience. It also includes an email compatibility analyzer that validates HTML rendering, checks link integrity, and s
This project is an email alias management platform and masking proxy designed to protect user privacy. It functions as a gateway that creates unique email addresses to hide a user's primary mailbox, forwarding incoming messages while routing outbound replies through a reverse-proxy to maintain sender anonymity. The system distinguishes itself through advanced domain and privacy controls, including the ability to link personal domains via DNS for branded aliases and catch-all routing. It further secures communications via a PGP encryption gateway that encrypts forwarded email content using pub
Roundcube is an open-source, self-hosted webmail client designed for reading, composing, and organizing emails stored on remote servers using IMAP and SMTP protocols. It provides a browser-based interface that allows users to manage their mailboxes and sender identities through a secure communication platform. The platform is distinguished by its modular architecture, featuring a plugin-based extension system for adding new functional modules and a skin-based theme layer for customizing the visual appearance and responsive layouts. It further supports embedding its interface into external clo
GAM is a command-line tool for administering Google Workspace and Cloud Identity. It translates command-line arguments into structured API calls, enabling administrators to manage users, groups, organizational units, and domain settings across a Google Workspace environment. The tool handles authentication through OAuth2 flows, service accounts, and workload identity federation, and supports multi-tenant configurations for managing multiple domains or cloud projects from a single installation. GAM distinguishes itself through its batch processing and automation capabilities. It can process la
Zero is an email automation and link management platform designed for self-hosted infrastructure. It functions as an intelligent system that categorizes, prioritizes, and responds to incoming email communications using autonomous agents, while synchronizing message history into local storage for efficient data processing. The platform distinguishes itself by integrating enterprise identity providers to manage team access and permissions across shared resources. It also features a comprehensive link management toolset that generates branded URLs and personalized QR codes, supported by advanced
Rainloop Webmail is a self-hosted, browser-based email application that connects to external mail servers using IMAP and SMTP protocols. It operates as a stateless client, fetching data directly from servers without requiring a local database to store messages. The system supports multi-account email management, allowing users to link multiple email identities to a single session for simultaneous access across different browser tabs. It includes a plugin-based extension system and tools for user interface customization and branding. The application provides capabilities for email workflow au
Mailpile is an encrypted email client and high-volume mail indexer that provides a web-based portal for managing electronic mail. It functions as a private email management system designed to protect user privacy and data control. The project features a search engine optimized for indexing and retrieving large volumes of email on consumer hardware. It includes a Bayesian email filter for automated message classification and tagging. The system supports secure communication through the integration of public-key encryption and signing for sending and receiving messages. Additional capabilities
eShopOnDapr is a reference architecture for building distributed .NET microservices. It demonstrates how to implement cloud-native application patterns by utilizing sidecar processes to handle infrastructure concerns, allowing individual services to remain decoupled from the underlying environment. The project provides a practical implementation of service-to-service communication, state management, and asynchronous messaging. By using a sidecar-based approach, it offloads tasks like service discovery and state synchronization, enabling independent services to interact reliably across distrib
SwanLab is an open-source machine learning experiment tracking platform and observability tool. It provides a centralized dashboard for logging training metrics, hyperparameters, and hardware performance to monitor and analyze AI model training runs. The platform is distinguished by its focus on self-hosted infrastructure, allowing users to deploy private instances via Docker or Kubernetes for secure on-premises data control. It also includes specialized utilities for migrating historical experiment logs and synchronizing real-time metrics from external tools like MLflow. The system covers a
PhotoPrism is a self-hosted digital asset management platform designed to organize, classify, and manage large collections of photos and videos on personal infrastructure. It functions as a private alternative to cloud-based services, ensuring that all media remains under the user's control. The platform utilizes neural-network-based media analysis to automatically detect objects, faces, and locations, providing a comprehensive, AI-powered approach to library organization. The project distinguishes itself through its containerized architecture, which simplifies deployment and lifecycle manage
This project is an enterprise-grade Java framework designed for building scalable, full-stack e-commerce applications. It provides a comprehensive foundation for microservice-based distributed architectures, enabling the development of complex retail platforms that include product management, order processing, and secure user authentication. By leveraging modular service patterns and centralized API gateways, the framework supports the construction of resilient systems that decompose monolithic business logic into independent, manageable services. The platform distinguishes itself through a r
This project is a disposable email inbox service built to run entirely on Cloudflare's edge network. It creates temporary email addresses that automatically receive and store incoming messages and attachments, all without managing any traditional server infrastructure. The service uses Cloudflare Workers for serverless processing, Durable Objects for persistent inbox state, and Workers KV for storing email data, with attachments handled through R2 object storage. The service distinguishes itself through a comprehensive set of access and management features. Users can authenticate through mult
Register is a GitOps domain registrar and subdomain registration service that uses version-controlled configuration files to manage domain ownership and mappings. It functions as a DNS management system and record orchestrator, utilizing JSON-based declarative configurations to programmatically update A, CNAME, MX, and TXT records. The project distinguishes itself through a registration process where domain ownership and subdomain assignments are stored as the source of truth within Git repositories. It includes an automated SSL provisioning tool to configure web servers and security certific
Gogs is a self-hosted Git service and collaborative code hosting platform. It functions as a version control manager that allows users to store and manage source code on their own infrastructure using SSH, HTTP, and HTTPS protocols. The platform distinguishes itself through comprehensive mirroring capabilities, acting as a tool to synchronize and mirror repositories and wikis from external hosting providers to a local instance. It is designed for secure, containerized deployment, supporting non-root user configurations to meet strict security requirements. Beyond basic hosting, it provides a
Symfony is a full-stack web framework designed for building scalable and maintainable server-side applications. It provides a comprehensive collection of decoupled components that form a foundational architecture, centered on a robust dependency injection container and a configuration-driven routing engine. By organizing code into modular services, the framework ensures that application components remain testable and loosely coupled throughout the development lifecycle. The framework distinguishes itself through an event-driven kernel architecture that allows developers to intercept and modif
An MCP server application that sends various types of messages to the WeCom group robot.