About Delivr

Delivr is a next-generation email client for personal and professional team use. It connects to your existing email server over standard IMAP and SMTP, so your data stays where you want it — while the experience feels modern, fast, and native.

The idea

Most webmail clients are either closed SaaS products or old, slow interfaces. Delivr bridges the gap: a Progressive Web App that feels like a modern mail client, combined with a self-hosted backend that never stores your mail on disk.

What makes Delivr different

• Open source everything — licensed under AGPL-3.0. Both the API and the web client are public on GitHub.
• Works with any mail server — as long as your provider or self-hosted server speaks IMAP and SMTP, Delivr can talk to it.
• Privacy-first design — mail content and attachments are streamed from IMAP, parsed in memory, and never cached on the backend filesystem or database.
• Type-safe from API to UI — the backend publishes an OpenAPI spec at runtime, and the frontend client is generated from it.
• Installable PWA — add Delivr to your home screen or desktop and get an offline-capable, auto-updating app shell.

Architecture overview

Delivr is split into two repositories that work together:

1. The browser loads Delivr Web from your chosen public URL. It handles login, the mail UI, and settings.
2. The web app calls Delivr API for every mail operation. The API authenticates the user, encrypts mail-server credentials, and proxies IMAP/SMTP traffic.
3. The API fetches live mail data from your configured IMAP/SMTP server, so nothing proprietary sits between you and your email.

Project values

• Respect for standards. We use plain IMAP, SMTP, JWT, and HTTP.
• Respect for privacy. Mail is streamed, not archived. Analytics and tracking have no place in Delivr.
• Respect for operators. Configuration is simple, documentation is complete, and self-hosting is a first-class path.