Use Sendmux attachment workflows without wasting model context on base64. Use when uploading, downloading, reading, forwarding, or sending email attachments through Sendmux MCP, CLI, SDKs, or direct HTTP, especially when choosing file_path vs presigned upload URL vs inline base64, reading inbound attachments with mailbox_read_attachment, fetching short-lived download_url links, or attaching local files to outbound mail.
Use the Sendmux command-line interface for terminal-driven Sendmux work. Use when the user wants install commands, profiles, key-scope preflight, --json output, colon-namespaced Sendmux commands, request body/path/query/header flags, or CLI examples for Management, Mailbox, or Sending API operations.
Design and route Sendmux email workflows for AI agents, including skill installation, self-registration, secure agent credential-bundle storage, owner approval, and runtime email operations. Use when a user wants to give an AI agent its own inbox or email address, let an agent receive/search/triage/reply to mail, draft human-approved replies, send notifications, monitor mailbox state, or build email-based agent workflows even when the user does not mention Sendmux by name.
Sendmux setup, skill installation, API key validation, agent access, secure agent credential-bundle storage, and first-call guidance. Use when the user wants to install Sendmux tooling or skills, check whether an smx_root_, smx_mbx_, or smx_agent_ credential works, choose MCP vs CLI vs SDK, connect an agent to Sendmux email, configure auth, self-register an agent, or make the first harmless Sendmux API call from an agent, terminal, or application.
Work efficiently with one Sendmux mailbox from an AI agent. Use for reading, searching, counting, syncing, triaging, filing, deleting, threading, or replying from a mailbox with an smx_mbx_ key or scoped smx_agent_ token, especially when the user asks an agent to inspect an inbox, find relevant messages, mark messages, or continue from a prior mailbox sync state.
Manage Sendmux account-level resources with an smx_root_ key. Use for domains, mailbox provisioning, mailbox API keys, sending accounts, webhooks, billing, spend, delivery logs, incoming logs, metrics, and other team administration tasks; route mailbox reading, triage, sync, and replies to sendmux-mailbox-agent.
Configure Sendmux Model Context Protocol servers for AI agent clients, using hosted OAuth first when supported and secret-backed local env config otherwise. Use when the user wants to install sendmux-mcp, connect the hosted Sendmux MCP endpoint, run local stdio or HTTP MCP servers, set mailbox/management/sending key scopes, add bearer headers, or write MCP config for Claude Code, Cursor, Codex, VS Code/Copilot, Copilot CLI, Gemini CLI, Cline, or Windsurf/Cascade.
Send email with Sendmux, including owner-approved Sending-resource smx_agent_ tokens from claim-token exchange. Use when the user wants to send one email, send multiple emails, choose single vs batch sending, add idempotency keys, include attachments, compare HTTP Sending API vs SMTP, or use Sendmux MCP, CLI, SDK, or direct HTTP for outbound email.