Deepbluework
Deepbluework is a hosted business email and collaboration service for teams using a domain they already own. It provides custom-domain mailboxes with IMAP/SMTP access and 10 GB of storage per mailbox. Users can manage calendars, invitations, reminders, and browser-based video meetings, and create encrypted notes that can be shared through password-protected links. Administrators can add, suspend, and organize users, create distribution groups, view an organization chart, and manage domain settings and billing in a web dashboard. DomainConnect can automate DNS setup at compatible registrars; other domains can be configured with provided records. The service also supports forwarding selected mail to Chato.pro and access through standard IMAP/SMTP email clients. Deepbluework offers web, iOS, and Android access for businesses and small teams seeking email and related communication tools on a custom domain.
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SubsiMail
SubsiMail is a self-hosted cold email sequencing platform. Prospect lists, templates, connected inboxes, and all campaign data live in your own database, not a third-party SaaS. It's built as a self-hosted alternative to Instantly, Smartlead, lemlist, and Apollo, with flat per-inbox pricing instead of per-seat fees, full data ownership and export, no content review, and no third-party access to your contacts or campaigns. Runs as a single Docker container on any $5 VPS. Connect Gmail, Outlook, or any SMTP/IMAP inbox; build multi-step sequences with merge fields and reply detection; manage per-user roles (admin/manager/view-only) with a full audit trail; and integrate via a REST API with personal API keys. The first connected mailbox is free forever.
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lfr
lfr is self-hosted mail-server and newsletter software packaged as a single Go binary for Linux and macOS servers. It lets developers, self-hosters, and small teams host mailboxes for their domains, manage aliases and forwarding, search and reply to messages, and configure domain mail records. Newsletter tools support double-opt-in signup lists, Markdown-based issues, hosted archives and signup websites, one-click unsubscribe, bounce and complaint handling, and delivery through a configurable SMTP relay when direct sending is unavailable. The command-line interface runs locally or over SSH, with setup and diagnostic commands for server, DNS, and mail delivery tasks. lfr is distributed under the MIT license; the software itself is free, while users arrange and pay for their own server and any optional relay service.
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Sendmux
Sendmux gives AI agents their own inbox and a controlled way to send email. Each agent can receive messages, read threads, handle attachments, send replies, and react to new mail through signed webhooks or Server-Sent Events.
Teams can send through Gmail OAuth, Outlook OAuth, SMTP providers, or managed Amazon SES. Sendmux can spread sending across providers with weighted routing, sender-domain routing, health checks, failover, and quotas by second, minute, hour, or day.
Developers get Mailbox, Sending, and Management APIs, OpenAPI docs, SDKs, the sendmux CLI, MCP tools, and Sendmux Skills. The platform also covers tenant isolation, mailbox-scoped API keys, custom domains, logs, metrics, and usage-based pricing with no per-seat or per-mailbox fees.
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