# Mails.so — how to use (mcp.ai)

Connect your Mails.so account and use 3 tools for email straight from your AI agent. Connect with your own API key. Mails is an API service that provides powerful email validation capabilities to help maintain a clean and effective email list.

## Option A — via MCP (recommended)
Remote MCP endpoint (HTTP, streamable): `https://api.mcp.ai/p_mails_so?ms=1787291160000`
Add it as a custom/remote MCP connector in your client (Claude, Cursor, VS Code…), then authenticate when prompted. Once connected, ask the agent to use the server's tools (e.g. `mails_so_retrieve_batch_results`).

## Option B — via direct REST API
Base URL: `https://api.mcp.ai/api/mails_so`
Auth: `Authorization: Bearer sk_live_…` — create a workspace API key at https://mcp.ai/settings/api-keys
Discover endpoints: `GET https://api.mcp.ai/api/mails_so/_endpoints`

### Endpoints
- `POST https://api.mcp.ai/api/mails_so/retrieve/batch/results` — Tool to retrieve results of a bulk validation job. Use after submitting a batch and you have its ID.
  - body: { id: string }
- `POST https://api.mcp.ai/api/mails_so/validate/bulk/emails` — Tool to validate multiple email addresses in bulk. Use when you need to confirm deliverability of a list of emails at once.
  - body: { emails: string[] }
- `POST https://api.mcp.ai/api/mails_so/validate/single/email` — Tool to validate a single email address. Use when you need to check deliverability and quality details before sending an email.
  - body: { email: string }

## Example prompts
- "What can I do in Mails.so?"
- "Show me a summary of my Mails.so account"

## More
- Page: https://mcp.ai/mails_so
- Agent spec (llms.txt): https://mcp.ai/mails_so/llms.txt
- Postman collection: https://mcp.ai/mails_so/postman.json