# Send & Receive Emails with OpenAI Codex (/integrations/frameworks/codex) Related: [Send & Receive Emails with Claude Cowork](/integrations/frameworks/claude-cowork.md), [Send & Receive Emails with Claude Code](/integrations/frameworks/claude-code.md), [Send & Receive Emails with OpenClaw](/integrations/frameworks/openclaw.md), [Send & Receive Emails with Grok](/integrations/frameworks/grok.md), [Send & Receive Emails with Manus](/integrations/frameworks/manus.md), [Send & Receive Emails with Cursor](/integrations/frameworks/cursor.md) # Connect OpenAI Codex to AgentMail 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