Use Mailvett: Email Validation API for AI Agents MCP with OpenAI Codex CLI
Mailvett: validate emails. MX, provider, disposable/role/free flags, typo fix, verdict.
Remote MCP server (Streamable HTTP), nothing to install. Free: 50 free calls/day, no key · Paid: Cleaner $19/month; Growth $49/month; Agency $99/month; Cleaner yearly $190/year; Growth yearly $490/year; Agency yearly $990/year
Set it up
- Open ~/.codex/config.toml (create it if needed).
- Add the [mcp_servers] table shown and save.
- Start Codex; the server's tools are available to the agent.
- Ask a question the tools can answer.
Add to ~/.codex/config.toml:
[mcp_servers.mailvett]
url = "https://mailvett.cybermaxtools.com/mcp?via=use-with-codex"With a paid key:
[mcp_servers.mailvett]
url = "https://mailvett.cybermaxtools.com/mcp?via=use-with-codex"
env_http_headers = { "x-api-key" = "CYBERMAX_API_KEY" }env_http_headers maps the header to an environment variable name, so the key stays in your environment.
- ~/.codex/config.toml (or .codex/config.toml in a trusted project)
Tools you get
Endpoint checked 2026-10-09: https://mailvett.cybermaxtools.com/mcp answered an MCP initialize (protocol 2025-06-18) and tools/list with 1 tool, all marked read-only. No key was used and no tool was called.
| Tool | What it does | Required inputs |
|---|---|---|
validate_emails | Check up to 10 email addresses: syntax, whether the domain exists and has mail servers (MX), mail provider, disposable, role account (info@, sales@), free provider, likely typo with a suggested fix, domain age, SPF and DMARC. Returns verdict (deliverable_likely/risky/undeliverable/invalid), score 0-100 and reason codes per address. Does not verify that the mailbox itself exists. | emails |
Test the endpoint from a terminal
This lists the tools without a key and without calling any of them:
curl -s https://mailvett.cybermaxtools.com/mcp \
-H 'content-type: application/json' \
-H 'accept: application/json, text/event-stream' \
-d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'If it does not work
- Each server is its own [mcp_servers.<name>] table; keep the name to letters, digits, dashes and underscores.
- For a fixed header value instead of an environment variable, Codex also documents http_headers.
- The free tier has a daily limit (see the pricing line above); a paid key raises it.
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