RMS Mail: browser-first email with background synchronization

RMS Mail is a self-hosted platform for working with email, built around the idea of full autonomy, predictable performance, and separation of the interface from the mail infrastructure.

Unlike classic webmail solutions, RMS Mail does not rely on direct IMAP interaction in the user interface. All synchronization, indexing, and search operations are performed on the backend side, ensuring stable interface performance regardless of mail volume.

The problem with classic webmail

Traditional webmail systems work directly via IMAP, which leads to:

• the interface freezing on large folders;
• search becoming slow and unpredictable;
• bulk operations blocking the UI;
• performance depending on the mail server state;
• lack of stable handling of large archives.

RMS Mail solves this problem architecturally — by moving all heavy operations to the backend.

Architecture of the approach

RMS Mail splits the system into two layers:

• UI layer — responsible only for display and interaction;
• Backend layer — performs synchronization, indexing, and search.

All resource-intensive operations are performed asynchronously:

• IMAP synchronization in the background;
• streaming email processing;
• building search indexes;
• bulk operations via task queues.

This allows the interface to remain responsive regardless of mailbox size.

Three editions of RMS Mail

RMS Mail is developed as a product line for different use cases and load levels.

Mono — lightweight self-hosted email

A lightweight edition for a single user or small organizations.

Mono is designed for quick deployment and minimal infrastructure.

Features:

• one user = one mailbox;
• SQLite as local storage;
• no external dependencies (PostgreSQL, Redis, etc.);
• integrations: Telegram, MCP, AI;
• launch in 2–3 commands;
• runs on any VPS.

Suitable for developers, individual use, small workgroups and organizations, as well as small self-hosted scenarios without complex infrastructure.

Mono Pro — extended configuration for high loads

A high-performance edition for large email volumes and long-term operation in organizations and teams.

Mono Pro retains the one user = one mailbox model but adds an infrastructure layer for load scaling.

Features:

• optimized handling of large email archives;
• improved backend for indexing and search;
• asynchronous background operations;
• extensible administration part (in development);
• integrations: Telegram, MCP, AI;
• stable operation during long-term use without performance degradation.

Mono Pro is designed for users and organizations working with large volumes of email daily.

Unified — multi-account platform

A full-fledged multi-user platform for working with multiple email accounts in a single interface.

Unified extends the RMS Mail concept to the level of a workspace for handling large email streams.

Features:

• support for multiple email accounts;
• project groups and unified inboxes;
• PostgreSQL + Redis backend;
• Telegram, MCP, AI integrations;
• advanced administration logic;
• scalable architecture for businesses and teams.

Unified is the foundation for enterprise scenarios and future integrations.

Common principle

All editions are built on a unified architecture:

• asynchronous email processing;
• local indexed search;
• separation of UI and backend logic;
• no UX dependence on IMAP;
• ready for self-hosted deployment;
• ease of deployment.

The difference between editions is not in the code, but in the level of infrastructure and scalability.

Deployment

RMS Mail is delivered as a ready-to-use self-hosted solution:

• Docker images for all editions;
• ready-made docker-compose configurations;
• support for reverse proxy (Nginx, Caddy, Open Resty);
• documentation for production deployment;

Summary

RMS Mail is not webmail on top of IMAP.

It is an architecturally separated email system where the interface, synchronization, and data processing work independently of each other, ensuring stable performance regardless of email volume.