# How to integrate SMTPing MCP with Atomic Agent

```json
{
  "title": "How to integrate SMTPing MCP with Atomic Agent",
  "toolkit": "SMTPing",
  "toolkit_slug": "smtping",
  "framework": "Atomic Agent",
  "framework_slug": "atomic-agent",
  "url": "https://composio.dev/toolkits/smtping/framework/atomic-agent",
  "markdown_url": "https://composio.dev/toolkits/smtping/framework/atomic-agent.md",
  "updated_at": "2026-11-06T05:32:27.147Z"
}
```

## Introduction

Atomic Agent is an open-source AI agent that runs on your machine and supports local models through llama.cpp. Connect it to 1,500+ apps through Composio, including SMTPing.
This guide uses Atomic Agent's built-in Composio integration. You need Atomic Agent v0.5.6 or later, your own Composio API key, and a SMTPing account. See the [Atomic Agent documentation](https://atomicagent.io/docs/?cta_placement=atomic-agent-docs) for installation instructions.

## Also integrate SMTPing with

- [ChatGPT](https://composio.dev/toolkits/smtping/framework/chatgpt)
- [Claude Cowork](https://composio.dev/toolkits/smtping/framework/claude-cowork)
- [Hermes](https://composio.dev/toolkits/smtping/framework/hermes-agent)

## TL;DR

### How Atomic Agent connects to SMTPing
Atomic Agent connects to Composio's Tool Router over Streamable HTTP MCP. It discovers the tools needed for your request, and Composio handles account authentication.
Execution and account-connection tools follow Atomic Agent's configured approval policy. Review any approval prompt before allowing an action on your connected account.

## Connect SMTPing to Atomic Agent

### Connect SMTPing to Atomic Agent
- Sign up or sign in to the [Composio dashboard](https://dashboard.composio.dev/?cta_placement=atomic-agent-api-key). Copy your API key.
- In Atomic Agent, open the Integrations tab and select Composio. Select API key, press e, paste the key, and press Enter. The tools become available immediately, without a restart.
- Ask Atomic Agent to do something in SMTPing. It searches Composio for the right tool.
- On first use, open the sign-in link returned in the chat. Connect your SMTPing account, then return to Atomic Agent to continue.
### Headless setup
Add the following line to ~/.atomic-agent/.env, replacing YOUR_COMPOSIO_API_KEY with your key. Start Atomic Agent after saving the file.

```bash
COMPOSIO_API_KEY=YOUR_COMPOSIO_API_KEY
```

## What is the SMTPing MCP server, and what's possible with it?

The SMTPing MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your SMTPing account. It provides structured and secure access to email verification, threat-list checks, bulk jobs, credits, and usage data, so your agent can verify addresses, identify risky emails, process large lists, monitor credits, and review API usage on your behalf.
- Email address verification: Have your agent verify individual email addresses and review their deliverability status and domain flags.
- Threat-list screening: Direct your agent to check an email or a batch of up to 1,000 addresses against a selected SMTPing threat list.
- Bulk email processing: Instruct your agent to start large verification or threat-list jobs for up to 100,000 addresses, then check progress and retrieve the results.
- Risk and domain flag checks: Let the agent inspect all six SMTPing risk and domain flags for a specific email address.
- Credits and usage tracking: Have your agent check remaining credits, review aggregate usage, list recent API requests, or export usage history as a CSV file.

## Supported Tools

| Tool slug | Name | Description |
|---|---|---|
| `SMTPING_CHECK_EMAIL` | Check Email | Check one email address against one selected SMTPing threat list and report whether it matched. Consumes one credit; SMTPing limits synchronous calls to 10 per minute. |
| `SMTPING_CHECK_EMAIL_BATCH` | Check Email Batch | Synchronously check 1 to 1,000 email addresses against one selected SMTPing threat list and return all results. Consumes one credit per unique address; SMTPing limits synchronous calls to 10 per minute. |
| `SMTPING_CHECK_EMAIL_FLAGS` | Check Email Flags | Return all six SMTPing risk and domain flags for one email address in one request. Consumes one credit; SMTPing limits synchronous calls to 10 per minute. |
| `SMTPING_CREATE_BULK_CHECK_JOB` | Create Bulk Check Job | Start an asynchronous SMTPing threat-list check for 1 to 100,000 email addresses. Returns a job ID for status polling and consumes one credit per unique address. SMTPing limits job submissions to two per hour. |
| `SMTPING_CREATE_BULK_VERIFICATION_JOB` | Create Bulk Verification Job | Start asynchronous verification for 1 to 100,000 email addresses and return the job ID to use for status polling and result retrieval. Consumes one credit per unique address as work completes; duplicates and unknown results are free. SMTPing limits job submissions to two per hour. |
| `SMTPING_EXPORT_USAGE` | Export Usage | Download SMTPing usage history as a CSV file for the provider's default date range. No date filters are exposed because none are documented. |
| `SMTPING_GET_BULK_CHECK_JOB` | Get Bulk Check Job | Get progress and match counts for an asynchronous threat-list check job. Poll every 20 to 30 seconds until status is Succeeded or Completed before fetching results; polling is free. |
| `SMTPING_GET_BULK_CHECK_RESULTS` | Get Bulk Check Results | Return all address-level matches for a bulk threat-list check job after its status is Succeeded or Completed. Returns 409 while incomplete; fetching results is free. |
| `SMTPING_GET_BULK_VERIFICATION_JOB` | Get Bulk Verification Job | Get progress and summary counts for an asynchronous bulk verification job. Poll every 20 to 30 seconds until status is Succeeded before fetching results; polling is free. |
| `SMTPING_GET_BULK_VERIFICATION_RESULTS` | Get Bulk Verification Results | Return all address-level results for a bulk verification job after its status is Succeeded. Returns 409 while the job is incomplete; fetching results is free. |
| `SMTPING_GET_CREDITS` | Get Credits | Return the connected account's current credit balance, plan, and daily remaining credits. This free read is the balance source of truth. |
| `SMTPING_GET_USAGE` | Get Usage | Return aggregate request, email, credit, status, endpoint, and error usage for SMTPing's current default date range. No date filters are exposed because none are documented or verified. This account read is free. |
| `SMTPING_LIST_USAGE_REQUESTS` | List Usage Requests | Return the newest available page of individual SMTPing API request history, up to the provider default of 50 rows, with page metadata. No continuation input is exposed because request-side pagination parameters are undocumented and unverified. |
| `SMTPING_VERIFY_EMAIL` | Verify Email | Verify one email address and return its deliverability status and domain flags. SMTPing charges one credit unless the result is unknown and limits synchronous calls to 10 per minute. Source: https://smtping.com/openapi.json#/paths/~1verify~1single/post |

## Supported Triggers

None listed.

## Troubleshooting

### Why is my API key rejected?

Copy the key directly from the Composio dashboard. Atomic Agent requires ASCII characters because it sends the key in an HTTP header. Remove any extra characters introduced when copying.

### Why are Composio tools unavailable after saving a key?

Check that you use Atomic Agent v0.5.6 or later and that Composio is enabled in your configuration. A "composio": { "enabled": false } setting disables the integration while keeping the saved key on disk.

### Does Composio have a free plan?

The Hobby plan includes 100,000 tool calls per month. Composio-managed OAuth apps have a lower included allowance. See [Composio pricing](/pricing) for the current limits that apply to your connection.

## Complete Code

None listed.

## Conclusion

### Use SMTPing from Atomic Agent
With your account connected, ask Atomic Agent to work with SMTPing in natural language. You can connect more apps through the same Composio integration as you need them.
Visit the [Atomic Agent website](https://atomicagent.io/?cta_placement=atomic-agent-site) or inspect the [Atomic Agent source code](https://github.com/AtomicBot-ai/atomic-agent?cta_placement=atomic-agent-repo).

## How to build SMTPing MCP Agent with another framework

- [ChatGPT](https://composio.dev/toolkits/smtping/framework/chatgpt)
- [Claude Cowork](https://composio.dev/toolkits/smtping/framework/claude-cowork)
- [Hermes](https://composio.dev/toolkits/smtping/framework/hermes-agent)

## Related Toolkits

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- [GitHub](https://composio.dev/toolkits/github) - GitHub is a code hosting platform for version control and collaborative software development. It streamlines project management, code review, and team workflows in one place.
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- [Abuselpdb](https://composio.dev/toolkits/abuselpdb) - Abuselpdb is a central database for reporting and checking IPs linked to malicious online activity. Use it to quickly identify and report suspicious or abusive IP addresses.
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- [Appveyor](https://composio.dev/toolkits/appveyor) - AppVeyor is a cloud-based continuous integration service for building, testing, and deploying applications. It helps developers automate and streamline their software delivery pipelines.
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- [AWS Marketplace MCP](https://composio.dev/toolkits/aws_marketplace_mcp) - AWS Marketplace MCP provides MCP access to AWS Marketplace's cloud software, data, and services catalog. Use it to discover, compare, and evaluate 30K+ AWS Marketplace listings faster.
- [Azure Monitor Activity Log](https://composio.dev/toolkits/azure_monitor_activity_log) - Azure Monitor Activity Log is Azure's service that records management and control-plane events for a subscription. Use it to audit changes, troubleshoot issues, and track resource operations across your Azure resources.
- [Backendless](https://composio.dev/toolkits/backendless) - Backendless is a backend-as-a-service platform for mobile and web apps, offering database, file storage, user authentication, and APIs. It helps developers ship scalable applications faster without managing server infrastructure.
- [Baserow](https://composio.dev/toolkits/baserow) - Baserow is an open-source no-code database platform for building collaborative data apps. It makes it easy for teams to organize data and automate workflows without writing code.

## Frequently Asked Questions

### What are the differences in Tool Router MCP and SMTPing MCP?

With a standalone SMTPing MCP server, the agents and LLMs can only access a fixed set of SMTPing tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from SMTPing and many other apps based on the task at hand, all through a single MCP endpoint.

### Can I use Tool Router MCP with Atomic Agent?

Yes, you can. Atomic Agent fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right SMTPing tools.

### Can I manage the permissions and scopes for SMTPing while using Tool Router?

Yes, absolutely. You can configure which SMTPing scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

### How safe is my data with Composio Tool Router?

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your SMTPing data and credentials are handled as safely as possible.

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