# How to use Claude to verify an email list with looot

Check which addresses will accept mail before you send, one call per address, with the reason for each verdict.

## Connect looot to Claude

1. In Claude, open Customize, then Connectors.
2. Click "+ Add", then "Add custom connector".
3. Name it looot and paste the remote MCP server URL https://api.looot.ai/mcp. Click Continue.
4. Review the authentication settings Claude detects and click Continue. Under Authentication pick "Sign in now" or "Sign in when needed". Under OAuth client, Anthropic recommends "Use Claude's published identity". Click Add.
5. looot's sign-in page opens: sign in with your looot account and allow access. Runs are paid from your prepaid looot balance.

Anthropic's help center says custom connectors work on Free, Pro, Max, Ultra, Team and Enterprise, and a Free account can add one custom connector. On Team and Enterprise an Owner or Primary Owner adds it under Organization settings, Connectors, and each member then clicks Connect under Customize, Connectors.

In Claude Code instead: Add looot from your terminal with one command: `claude mcp add --transport http looot https://api.looot.ai/mcp`. Then type /mcp inside Claude Code and follow the browser sign-in.

- Source, read 2026-11-10: [Anthropic help center: Get started with custom connectors using remote MCP](https://support.claude.com/en/articles/11175166-getting-started-with-custom-connectors-using-remote-mcp)
- Source, read 2026-11-10: [Claude Code docs: Connect Claude Code to tools via MCP](https://code.claude.com/docs/en/mcp)

## Ask Claude

In a new chat, click the "+" button at the lower left, choose Connectors and switch looot on for this conversation. Then paste the prompt.

Use looot to check each email address below with the job people.email.verify, one call per address. Return a table with the address, the status and the reason the provider gave. Mark catch-all domains separately, because no provider can prove a single mailbox exists on them.

[One email address per line]

## Jobs it calls and what they cost

One use costs from $0.00025 at today's cheapest providers. A provider that misses can fall back to the next one, which can cost more; looot charges only the calls that ran, from your prepaid balance.

- `people.email.verify`: 1 call, from $0.00025 per call (Filtrat, the cheapest of 13 providers). Compare providers: [people.email.verify benchmark](/benchmarks/people-email-verify). [About the cheapest provider](/providers/filtrat)

## A real run

We ran this task through the looot MCP on 2026-11-10. Asked: p****@stripe.com, the address the work email guide found. Total charged: $0.

- people.email.verify on filtrat-verify-email (Filtrat): answered, rated weak, charged $0. Run id run_716a2c5bc35a4884ba49555682055e2e.
- Status: verified, confidence 98 out of 100. Not disposable, not a role address, syntax valid.
- The domain is catch-all and its mail runs on Google Workspace, so the mailbox itself cannot be proven.
- looot rated the answer weak and charged $0 for it.

## Good to know

- A catch-all domain accepts mail for any address, so a verifier can only say the domain works. looot counts that answer as weak, not as a hit.

## More

- [The same task in ChatGPT](/guides/chatgpt/verify-email-list)
- [The prompt on its own](/prompts/verify-email-list)
- [All Claude guides](/guides/claude)