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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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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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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Grace Mail
Grace Mail is email server software for teams that want control over their email infrastructure. It can be licensed as self-hosted software running on the customer's Linux hardware, or provided as a managed dedicated server operated by LINK-V. The product supports SMTP and IMAP and includes an administration console for managing mailboxes, domains and mail operations. Its two deployment approaches support organizations that want to operate their own server as well as teams that prefer the vendor to operate a dedicated server. Grace Mail is aimed at freelancers, small businesses and technical teams seeking company email on a dedicated or self-hosted server. The software is built and maintained by Profit Visions, and deployment, licensing, migration and support arrangements are agreed with each customer. Customers can assess the self-hosted or managed arrangement against their infrastructure preferences and operational responsibilities.
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