Zero unifies Gmail, Outlook, and IMAP accounts into a single AI-enhanced inbox with keyboard-driven navigation that matches premium email clients in speed. Backed by 10,000+ stars and positioned as the alternative to Superhuman, it keeps your email data in your own PostgreSQL database while LLM agents handle categorization, priority sorting, draft composition, and natural language mailbox queries. You choose whether models run locally or through cloud providers you control. The Next.js and React interface delivers customizable keyboard shortcuts for every action: reading, archiving, labeling, composing. A WorkflowEngine defines automated multi-step rules including label application, bulk archiving, and conditional routing based on sender, subject, or content analysis. Built on Drizzle ORM with Better Auth handling Google OAuth, styled with TailwindCSS and Shadcn UI components, the interface is polished without being bloated. MCP integration exposes email management tools to external AI assistants for programmatic inbox control through standardized protocols. The Nizzy CLI handles environment configuration, database synchronization, and development server orchestration. Deploys via Docker Compose with a single database initialization command. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Two decades of continuous development made Roundcube the standard-bearer of open-source webmail - a PHP IMAP client that gives any mail server a polished, application-like interface in the browser. It connects to whatever IMAP/SMTP stack you run - Dovecot, Postfix, a hosted mailbox - and delivers the full desktop-client experience: drag-and-drop message management, threaded conversation views, full MIME and HTML mail handling, find-as-you-type address book with groups and LDAP connectors, multiple sender identities, full-text search, and spell checking in dozens of languages. The default Elastic skin is genuinely responsive, working as well on a phone as a desktop, and the entire UI is skinnable. The plugin API is where deployments get shaped: managesieve exposes server-side filter management in the UI, enigma brings PGP encryption and signing via GnuPG, markasjunk trains spam filters, zipdownload batches attachments, password lets users change credentials, and attachment_reminder catches the classic forgotten-attachment email - among hundreds of community plugins. Built-in caching keeps large mailboxes fast, IMAP ACLs and shared folders support team setups, and XSS protection is engineered into the rendering pipeline. It scales from a single personal mailbox to unlimited users, backed by MySQL, MariaDB, PostgreSQL, or SQLite. GPL-licensed with regular security releases.

Built as a developer-first alternative to SendGrid, Mailgun, and Postmark, Posta delivers a complete self-hosted email infrastructure platform handling both outbound delivery and inbound reception through a single HTTP API with official SDKs for Go, PHP, and Java. The Go backend processes email through Redis and Asynq with automatic retries, priority queues, and async delivery while PostgreSQL stores templates, contacts, campaigns, and delivery analytics. Outbound features include versioned multi-language templates with variable substitution and stylesheet inlining, bulk campaigns with subscriber targeting and A/B testing per-variant metrics, scheduled timezone-aware delivery with draft/paused/cancelled lifecycle states, email address verification checking syntax, MX records, disposable domains, and role accounts, plus web view links with signed expiring URLs and one-click unsubscribe headers. The built-in SMTP receiver with TLS handles inbound email at your domains, parses messages and attachments, scores spam, and forwards structured payloads to your application via HMAC-verified webhooks with real-time SSE notification streams. The Vue-based dashboard manages templates, SMTP server pools, domains, contacts, API keys, campaigns, and email logs with dark and light mode support while admin-level platform metrics expose delivery rate trends, bounce rate graphs, and latency percentiles alongside Prometheus integration and daily health reports. Deploy via Docker with PostgreSQL and Redis. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache 2.0 licensed.

SendPortal is a self-hosted email marketing platform for building subscriber lists, sending campaigns, and tracking exactly what happens to every message after it leaves your server. Grow the list three ways: add contacts one by one, import them in bulk from CSV, or push them through the API, which creates or updates subscribers by email address and attaches tags. Tags and custom segments organize audiences, sending product updates to power users and sale announcements to everyone else. A campaign pairs a subject line, which can insert first name, last name, and email placeholders, with an optional HTML template holding content, unsubscribe, and browser view placeholders. Automatic CSS inlining at dispatch keeps designed emails rendering properly in inboxes that ignore style sheets. Send a test email to yourself before anything goes out, then choose immediate delivery or schedule the campaign for later. Pick Queue Draft to review messages before they leave, or Send Automatically when the audience and content are already right. Open and click tracking, bounce records, and unsubscribe events then flow back through provider webhooks into per campaign reports and a searchable message log. Run several brands or clients side by side in separate workspaces inside one interface. Delivery runs through Amazon SES, Postmark, SendGrid, Mailgun, Mailjet, or your own SMTP server, so deliverability stays with providers built for it. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Add a live support desk to any website with Live Helper Chat, where visitors talk to operators or bots and you own every transcript. Site owners paste a generated embed snippet into any page, and the start-chat fields are customizable. Chats are routed by department, language, location, or custom attributes, wait in a priority queue, and move between agents. Operators, departments, and simultaneous chats are unlimited. Agents watch a visitor type before the message is sent, read pages visited and time on site in the online visitors list, and send proactive invitations to people who linger. Voice, video, and screen sharing run through Jitsi or Agora, and a screenshot shows what the visitor sees. Bot designers chain triggers and actions in a visual builder, call ChatGPT, Gemini, Ollama, Rasa, or any REST API, and hand the conversation to a person when needed. Incoming email becomes tickets beside chats, and extensions connect Telegram, WhatsApp, Facebook Messenger, and Twilio SMS. Staff answer from the browser, a desktop app, a Chrome extension, or iOS and Android apps. Management tools include roles, groups, statistics, transcripts, and an archive, and extensions add two-factor login, LDAP, and single sign-on. It suits banks, healthcare teams, universities, and game studios that must keep chat data in house. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.

MillionSend is an open-source email platform you run yourself that sends transactional and marketing mail through your own AWS SES account behind a Resend-compatible API. Every message you send becomes a row in the dashboard, and every row opens into a timeline of SES events with the raw payload and the SMTP diagnostic when something bounces. Daily metrics chart sent, delivered, opened, clicked, bounced, and complained volumes against SES thresholds, and broadcasts stop on their own at five percent bounces or 0.1 percent complaints before Amazon can pause your account. Contacts live once for the whole team with custom properties and subscribe state, while segments and topics decide exactly who receives each broadcast. You compose broadcasts from reusable templates with per-contact merge fields, schedule them ahead, and cancel them while they wait. Applications that only speak SMTP send through the relay on port 2587 with an API key as the password, and HTTP integrations use idempotency keys, request logs with secrets redacted, and signed webhooks with a delivery history. Guided domain setup handles DKIM records, hard bounces and complaints are suppressed automatically, and every recipient gets an RFC 8058 one-click unsubscribe. Receiving and agent-ready inboxes are included in beta for mail sent to your verified domains. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.

DispatchMail is an SuperHuman alternative and delivers a self-hosted AI email assistant that processes your Gmail inbox through configurable OpenAI prompts without sending data to third-party cloud services beyond the LLM API itself. The Flask backend connects to Gmail via IMAP, retrieves new messages according to your schedule, and routes them through customizable whitelist rules based on sender address, subject keywords, or natural language descriptions before AI processing begins. Two distinct prompt configurations control behavior — the Reading Prompt instructs how the AI should analyze and classify incoming messages, while the Draft Prompt defines how responses should be composed, letting you maintain consistent tone and policy across all automated replies. Whitelist filtering ensures the AI only processes messages you explicitly authorize, preventing unnecessary API costs and keeping sensitive emails out of the LLM pipeline entirely. The React web interface provides inbox management with message previews, AI-generated summaries, draft editing with human-in-the-loop approval before sending, and configuration panels for prompts and rules. Automatic labeling and archival organize processed messages into categories without manual intervention. The sender research feature uses LLM-powered deep analysis to build background profiles of email contacts. All email content, credentials, and processing results persist in a local SQLite database with zero cloud storage dependencies. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. Apache-2.0 licensed.

Your entire mail system can live in one self-hosted suite with OpenMail, from SMTP, IMAP, and POP3 delivery to three-pane webmail and the admin console that runs it. Standard clients such as Thunderbird, Apple Mail, and phone apps connect over SMTP ports 25, 587, and 465, IMAP ports 143 and 993, and POP3 ports 110 and 995, while people use the three-pane webmail with folder tree, conversation list, and reading pane at port 3000. You read, write, reply, forward, batch-organize, drag messages between folders, filter stars, search sender, subject, and body text, and follow conversations threaded automatically by their References headers. The rich-text composer autocompletes recipients, accepts dragged attachments and pasted screenshots, saves drafts every 12 seconds, sends on a schedule, and inserts reusable templates imported from HTML or generated with AI. Any OpenAI-compatible endpoint can draft replies, translate mail into twelve languages, and summarize messages, with provider keys encrypted on your server. Administrators get real-time mail statistics with 14-day send and receive trends, user quotas and bans, multi-domain aliases and catch-all addresses, outgoing queue visibility, and audit logs. Adding a domain generates DKIM keys and copy-ready SPF, DKIM, and DMARC DNS records with one-click checks, while rule-based spam scoring, TOTP two-factor authentication, and role-based permissions protect accounts in ten interface languages including right-to-left Arabic and Urdu. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Email discussion lists - the venerable listserv pattern where one address relays to a whole group - without the notorious setup pain of Mailman or Sympa: that is Gray Duck Mail. Its architectural trick is requiring no mail server of your own: the C#/ASP.NET Core app monitors a POP3 inbox at any external email host supporting POP3/SMTP and aliasing, relays each incoming message to all list members via SMTP, and archives it for browsing in the web interface. Replies route back to the entire group automatically. The tedious parts of list management are handled by convention: dedicated aliases process join requests, subscription confirmations, and unsubscribes, while a bounce alias in the return-path catches delivery failures so dead addresses get handled instead of silently rotting. The web administration interface creates and removes lists, manages contacts, browses message archives, and imports or exports the local database for backup. GPLv3-licensed, Docker-distributed, and fully code-documented, it targets exactly the groups email still serves best - neighborhoods, schools, congregations, workplaces, and families - where one message keeping everyone in the loop beats yet another app nobody wants to install.