# email.validate

Validate an email address: RFC syntax validity, normalized address with local/domain, and flags for isDisposable (throwaway domain), isRoleAccount (info@/support@/…), isFreeProvider (gmail/outlook/…). With checkMx (default true) also reports hasMxRecords (domain MX presence, via DNS-over-HTTPS) + MX hosts. NOT a deliverability or mailbox-existence guarantee — signals only. For signup hygiene and lead scrubbing.

Agent View of the PolicyLayer registry record for `email.validate`. HTML page: https://policylayer.com/tools/io-github-2s-io-mcp/email.validate

## Facts

- Tool: `email.validate`
- Server: Mcp (`@2sio/mcp`) — https://policylayer.com/tools/io-github-2s-io-mcp.md
- Install: `npx -y @2sio/mcp`
- Homepage: https://github.com/2s-io/sdk
- Risk category: Read (Low risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Allowed

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "email.validate",
    "arguments": {}
  }
}
```

## Why email.validate is rated Low

This is a validation and information-retrieval tool. It queries email syntax, performs DNS lookups for MX records, and returns classification flags—all read-only operations with no capability to modify, delete, execute code, or affect financial state. The explicit disclaimer that it provides 'signals only' and makes no guarantees confirms it is purely informational.

From the tool's own definition: "Tool description explicitly states it 'Validate[s] an email address' and 'reports' on syntax, normalization, disposability flags, and MX records. It performs DNS queries (DNS-over-HTTPS for MX records) and analysis only."

## Use case

AI agents call email.validate to retrieve information from Mcp without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

## Recommended policy (PolicyLayer)

Verdict: **Allowed**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Mcp:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "email.validate": {}
  }
}
```

## Other tools on Mcp (571)

- `queue.ack` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/queue.ack.md
- `store.blob-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.blob-delete.md
- `store.doc-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.doc-delete.md
- `store.kv-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.kv-delete.md
- `store.vector-delete` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/store.vector-delete.md
- `watchers.cancel` — Destructive — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.cancel.md
- `ai.council` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/ai.council.md
- `ai.screenshot` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/ai.screenshot.md
- `batch.run` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/batch.run.md
- `dev.preflight` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/dev.preflight.md
- `dev.regex-test` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/dev.regex-test.md
- `hash.compute` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/hash.compute.md
- `pubsub.subscribe` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/pubsub.subscribe.md
- `queue.lease` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/queue.lease.md
- `search.crawl` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/search.crawl.md
- `url.render` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/url.render.md
- `watchers.crypto-address-activity` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.crypto-address-activity.md
- `watchers.earthquake` — Execute — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.earthquake.md
- `predict.crypto-updown` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/predict.crypto-updown.md
- `predict.wallet` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/predict.wallet.md
- `watchers.fear-greed` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.fear-greed.md
- `watchers.fx-rate` — Financial — https://policylayer.com/tools/io-github-2s-io-mcp/watchers.fx-rate.md
- `agent.knowledge-delta` — Other — https://policylayer.com/tools/io-github-2s-io-mcp/agent.knowledge-delta.md
- `agriculture.drought` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/agriculture.drought.md
- `agriculture.stats` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/agriculture.stats.md
- `ai.chat` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.chat.md
- `ai.classify` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.classify.md
- `ai.describe-image` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.describe-image.md
- `ai.entities` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.entities.md
- `ai.extract` — Read — https://policylayer.com/tools/io-github-2s-io-mcp/ai.extract.md
- …and 541 more: https://policylayer.com/tools/io-github-2s-io-mcp.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=io-github-2s-io-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/io-github-2s-io-mcp