Email Inbox API + Sending by Sendmux MCP Server

Official SDK, CLI, and MCP workspace for Sendmux. Product documentation: sendmux.ai/docs Management API reference: sendmux.ai/docs/api/introduction Mailbox API reference: sendmux.ai/docs/mailbox-api/introduction Sending API reference: sendmux.ai/docs/sending-api/introduction MCP guide: sendmux.ai/docs/ai-integrations/mcp

People who work with cli tool, email and inbox and want it reachable from Claude, Cursor, VS Code, or another MCP client. The project is written in PHP.

VERIFIED ACTIVE

LAST COMMIT 2026-09-18 · ★ 73 · #10 OF 90 MAINTAINED EMAIL · VERIFIED 2026-09-18

MIT · PHP · how we verify → /methodology

01 · Install Email Inbox API + Sending by Sendmux

before you install - you'll need

The README does not document required environment variables for a basic install.

Claude Code

claude mcp add sendmux-sendmux-sdk --transport http https://mcp.sendmux.ai/mcp

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "sendmux-sendmux-sdk": {
      "url": "https://mcp.sendmux.ai/mcp"
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

https://mcp.sendmux.ai/mcp

transport: streamable-http

endpoint alive - authentication required · probed 2026-09-17

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions · remote - your agent's requests go to mcp.sendmux.ai

endpoint auth requires authentication - rejected our unauthenticated MCP initialize

license MIT - declared in the repository

pypi package sendmux-mcp - check the name against the project README before installing (PyPI has no namespace ownership)

registry namespace io.github.Sendmux is GitHub-verified and matches the repo owner

03 · What Email Inbox API + Sending by Sendmux can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

Latest releases

ts-sending-v1.6.0 · 2026-09-18

1.6.0 (2026-09-18) · integrate combined provider variables and delivery routing · add provider variables and delivery group routing · preserve attachment idempotency across composite sends · bound attachment file reads…

python-sdk-v3.0.0 · 2026-09-18

3.0.0 (2026-09-18) · python-sdk: provider lists expose ProviderListItem while details retain ProviderItem with variables. Requires Management 2 and prepares the SDK 3 release; published SDK versions remain immutable.…

ts-management-v2.0.0 · 2026-09-18

2.0.0 (2026-09-18) · Changed · managementListProviders returns ProviderListItem entries without variables, while managementGetProvider returns ProviderItem with required variables. List entries no longer satisfy the…

04 · Who maintains Email Inbox API + Sending by Sendmux

Email Inbox API + Sending by Sendmux is maintained by sendmux. It's the only MCP server we track from this author; the repo dates to May 2026.

05 · Facts

repository: github.com/sendmux/sendmux-sdk
website: https://sendmux.ai/docs/guides/mcp
category: email - ranked #10 of 90 actively-maintained email servers as of 2026-09-18.
release cadence: 10+ releases in the last 90 days (latest 2026-09-18)
registry: io.github.Sendmux/sendmux-mcp (active, first published 2026-06-19 · 15 versions)
packages: pypi:sendmux-mcp

06 · Email Inbox API + Sending by Sendmux FAQ

What is Email Inbox API + Sending by Sendmux?

Is Email Inbox API + Sending by Sendmux still maintained?

Yes - as of 2026-09-18, its last commit was 2026-09-18 and it shipped 10+ releases in the last 90 days. We re-verify nightly.

How do I install Email Inbox API + Sending by Sendmux?

Run `uvx sendmux-mcp`. The README does not document required environment variables for a basic install. You can also paste the ready-made client config above.

Does Email Inbox API + Sending by Sendmux require authentication?

Yes - when we probed the endpoint on 2026-09-17, it rejected an unauthenticated MCP initialize; you'll need credentials to connect.

07 · Alternatives to Email Inbox API + Sending by Sendmux

Alternatives to Email Inbox API + Sending by Sendmux

Maintained email servers if Email Inbox API + Sending by Sendmux isn't the fit.

More email MCP servers · AI · Sendsoon MCP Server · Sequenzy MCP · Abnormal Security MCP · Proton Mail (unofficial)