> ## Documentation Index > Fetch the complete documentation index at: https://agentmail.manicule.dev/llms.txt > Use this file to discover all available pages before exploring further. > For every page in one file, fetch https://agentmail.manicule.dev/llms-full.txt (large). > To search and read these docs as tools, connect the MCP server at https://agentmail.manicule.dev/api/mcp. > Every agent surface: https://agentmail.manicule.dev/.well-known/llms-manifest.json # Send & Receive Emails with OpenAI Codex (/integrations/codex) Related: [Send & Receive Emails with Claude Cowork](/integrations/claude-cowork.md), [Send & Receive Emails with Claude Code](/integrations/claude-code.md), [Send & Receive Emails with OpenClaw](/integrations/openclaw.md), [Send & Receive Emails with Grok](/integrations/grok.md), [Send & Receive Emails with Manus](/integrations/manus.md), [Send & Receive Emails with Cursor](/integrations/cursor.md) # Connect OpenAI Codex to AgentMail > Use the AgentMail plugin directly in OpenAI Codex to send and receive emails Installing the AgentMail plugin gives Codex the hosted MCP server and the AgentMail skills in one install, so it can create `@agentmail.to` inboxes, send email, and check replies from a session. Use this path for the Codex CLI or the ChatGPT desktop app, and the API-key options below for shared machines, CI, and Codex cloud tasks. ## Do this Requires an AgentMail account (create one at `https://console.agentmail.to`). The plugin authenticates with OAuth, no API key needed. ```bash npm install -g @openai/codex codex login codex plugin marketplace add agentmail-to/agentmail-plugins codex plugin add agentmail@agentmail # optional: sign in to AgentMail ahead of time instead of letting # the first tool call open the browser sign-in codex mcp login agentmail ``` Start a new Codex session after installing, complete the browser sign-in on the AgentMail page if prompted, then test with the prompt `List my AgentMail inboxes.` ## Facts * The plugin bundles the AgentMail skills and the hosted MCP server at `https://mcp.agentmail.to/mcp`. One install adds both. * ChatGPT desktop app: install from the Plugins tab. Search for AgentMail, select the plus button, start a new chat. * `codex plugin list` shows the install as `agentmail@agentmail installed, enabled`. * `codex mcp list` shows the connection. The `Auth` column reads `Not logged in` until the browser sign-in finishes. * `/mcp` inside a session lists the AgentMail tools Codex can call. * Accounts in more than one organization: ask Codex to list organizations and select the one to work in. Signed-in sessions include tools for both. * Skills: `$send-email` drafts and delivers mail, `$check-email` reads and triages it, `$manage-inboxes` handles the inbox lifecycle. Codex picks one on its own, or type `$` in the composer to invoke one by name. * Skills treat email content as untrusted data. Compose requests create drafts rather than sending. Sends require explicit or previously confirmed details. Inbox deletion requires confirming the exact address. * Inbox usernames are first come, first served. Skipping the username always works because AgentMail generates the address. * API key alternative when a browser sign-in is not possible: configure the local bridge in `~/.codex/config.toml` and export `AGENTMAIL_API_KEY` in the shell that starts Codex (`env_vars` passes it through). Keys come from `https://console.agentmail.to/dashboard/api-keys`. ```toml [mcp_servers.agentmail] command = "npx" args = ["-y", "agentmail-mcp"] env_vars = ["AGENTMAIL_API_KEY"] ``` * Codex cloud tasks run in isolated containers configured per repository at `https://chatgpt.com/codex/settings/environments`. Give them email access with an API key and the AgentMail CLI: 1. Add `AGENTMAIL_API_KEY` as an environment variable. Environment variables stay set for the whole task. 2. Install the CLI in the environment's setup script (setup scripts run with internet access): `npm install -g agentmail-cli` 3. Turn on agent internet access for the environment and add `api.agentmail.to` to the allowed domains. ## Not supported * `codex exec` denies tool approvals by default, and sending a message asks for one. Pass `--approve-for-me` for non-interactive runs. * Cloud task agents have no internet access by default. Without `api.agentmail.to` on the environment's allowed domains, the task cannot reach AgentMail. * Cloud task secrets are decrypted only for setup scripts and removed before the agent starts. Store `AGENTMAIL_API_KEY` as an environment variable, not a secret, when the agent needs it while it works. * Asking Codex to compose an email creates a draft, it does not send. ## Errors | Error | HTTP status | Cause | Fix | | --------------------- | ----------------------- | ------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------ | | `403` on inbox create | 403 | Requested inbox username is taken (first come, first served) | The error reaches Codex as a tool result naming up to three available variants in `suggestions`. Retry with one or skip the username | | `limit_exceeded` | not stated on this page | Inbox count is at the plan's cap | Returned instead of the username error. Stay under the plan's inbox cap | ## Verify ```bash codex plugin list ``` A row reading `agentmail@agentmail installed, enabled` confirms the install. In a new session, the prompt `List my AgentMail inboxes.` returning your inboxes proves the whole path works. ## Related * `/integrations/mcp-and-skills` - full hosted tool catalog and configuration for every other client * `/core/send` - the send, list, and reply commands a cloud task runs with the CLI