MCP Server
MCP Server for email checker. Integrate email verification with Claude, Cursor, and AI assistants.
Model Context Protocol (MCP) is an open protocol by Anthropic that enables AI models to securely interact with external tools and data sources. EmailVerify provides enterprise-grade email verification capabilities for AI agents through HTTP Streamable Transport, making integration incredibly simple.
Why AI Agents Need Email Verification
Modern AI agent use cases include:
- Claude Code needs to verify email addresses when processing user data
- OpenCode requires email validation in automated workflows
- Gemini CLI agents need quality assurance when handling registration data
- Codex generated code needs built-in email verification logic
- Custom AI Agents need to confirm contact authenticity when interacting with humans
EmailVerify MCP enables any AI agent to directly call enterprise-grade email verification services through the HTTP Streamable Transport standard - no complex configuration required.
Core Features
1. Single Email Real-time Verification
- Verify email format, domain, and MX records
- Optional SMTP connection check
- Disposable email detection
- Company vs free email identification
- Role-based email detection (support@, noreply@, etc.)
- Average response time < 2 seconds
2. Batch Email Verification
- Verify up to 50 emails at once
- Concurrent processing for efficiency
- Detailed results and statistics
3. Smart Caching System
- Valid emails cached for 7 days
- Invalid emails cached for 7 days
- Unknown status cached for 10 minutes
- Reduces unnecessary repeated verifications
4. Precise Credit Billing
- Valid email: 1 credit
- Invalid email: 0 credits (prevents waste)
- Unknown status: 0 credits (auto-retry)
- Real-time balance queries
Supported AI Clients
| Client | Type | Status | Description |
|---|---|---|---|
| Claude Desktop | Desktop App | Supported | Mac/Windows desktop application |
| Claude Code | CLI | Supported | Anthropic's CLI programming assistant |
| OpenCode | CLI | Supported | Open-source AI coding assistant |
| Gemini CLI | CLI | Supported | Google's command-line AI agent |
| Codex | CLI | Supported | OpenAI's code generation agent |
| Cursor | IDE | Supported | AI-powered code editor |
| Zed | IDE | Supported | High-performance code editor |
| Cline (VS Code) | Extension | Supported | VS Code AI extension |
| Continue | Extension | Supported | Open-source AI assistant |
| Windsurf | IDE | Supported | AI-native code editor |
| Droid | CLI | Supported | Android development AI assistant |
Quick Setup (HTTP Transport - Recommended)
The simplest way to integrate - no npm packages to install!
Step 1: Get API Key
Visit the EmailVerify Dashboard to create your API key.
Step 2: Configure Claude Desktop
Edit the configuration file:
macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%\Claude\claude_desktop_config.json
{
"mcpServers": {
"emailverify": {
"command": "curl",
"args": ["--stdio", "https://mcp.emailverify.ai/mcp?api_key=YOUR_API_KEY"]
}
}
}Replace YOUR_API_KEY with your actual API key, then restart Claude Desktop.
That's it! No npm install, no dependencies. curl is pre-installed on all systems. Claude now has email verification capabilities.
Step 3: Start Verifying
In your conversation, simply ask:
Please verify this email: user@example.comClaude will automatically call EmailVerify and return detailed results.
Claude Code Setup
For Claude Code CLI, add the MCP server:
claude mcp add emailverify -- curl --stdio "https://mcp.emailverify.ai/mcp?api_key=YOUR_API_KEY"Or add to your ~/.claude.json:
{
"mcpServers": {
"emailverify": {
"command": "curl",
"args": ["--stdio", "https://mcp.emailverify.ai/mcp?api_key=YOUR_API_KEY"]
}
}
}OpenCode Setup
For OpenCode, configure in your ~/.opencode/config.json:
{
"mcpServers": {
"emailverify": {
"command": "curl",
"args": ["--stdio", "https://mcp.emailverify.ai/mcp?api_key=YOUR_API_KEY"]
}
}
}Gemini CLI Setup
For Gemini CLI, add to your configuration:
{
"mcpServers": {
"emailverify": {
"command": "curl",
"args": ["--stdio", "https://mcp.emailverify.ai/mcp?api_key=YOUR_API_KEY"]
}
}
}Cursor Setup
In Cursor, go to Settings > MCP and add:
{
"emailverify": {
"command": "curl",
"args": ["--stdio", "https://mcp.emailverify.ai/mcp?api_key=YOUR_API_KEY"]
}
}NPX Method (Alternative)
If you prefer the npm package approach:
{
"mcpServers": {
"emailverify": {
"command": "npx",
"args": ["-y", "@emailverify/mcp-server"],
"env": {
"EMAILVERIFY_API_KEY": "your-api-key-here"
}
}
}
}Available Tools
verify_single_email
Verify a single email address with comprehensive validation.
Parameters:
| Parameter | Type | Required | Description |
|---|---|---|---|
| string | Yes | Email address to verify | |
| check_smtp | boolean | No | Enable SMTP verification (default: false) |
| force_refresh | boolean | No | Bypass cache for fresh result (default: false) |
Returns:
{
"email": "user@example.com",
"status": "valid",
"score": 1,
"is_deliverable": true,
"is_disposable": false,
"is_catchall": false,
"is_role": false,
"is_free": true,
"domain": "example.com",
"mx_records": ["has_mx_records"],
"smtp_check": true,
"response_time": 2,
"credits_used": 1
}Example usage in Claude:
"Check if test@example.com is a valid email"
verify_batch_emails
Verify multiple email addresses at once (max 50).
Parameters:
| Parameter | Type | Required | Description |
|---|---|---|---|
| emails | string[] | Yes | Array of email addresses (max 50) |
| check_smtp | boolean | No | Enable SMTP verification |
Returns:
{
"total_emails": 2,
"valid_emails": 2,
"invalid_emails": 0,
"results": [...],
"credits_used": 2,
"process_time": 4
}Example usage in Claude:
"Verify these emails: user1@example.com, user2@test.com, info@company.com"
get_account_balance
Check account credits and usage statistics.
Parameters: None
Returns:
{
"account_id": "acc_xxx",
"credits": 944815,
"total_consumed": 59325,
"total_added": 1000,
"last_updated": "2026-01-10T12:32:00Z"
}Example usage in Claude:
"How many verification credits do I have left?"
Usage Examples
Basic Verification
User:
Verify john@google.com
Claude:
I'll verify that email address for you.
Email Verification Result
Field Value john@google.com Status Valid Deliverable Yes Disposable No Score 0.95 This email appears to be valid and deliverable.
Multiple Email Verification
User:
Check these emails: john@google.com, test@mailinator.com, support@microsoft.com
Claude:
I'll verify all three email addresses.
Status Notes john@google.com Valid Deliverable, corporate email test@mailinator.com Invalid Disposable email, recommend rejecting support@microsoft.com Valid Role-based address, may be shared Recommendations:
- john@google.com - Safe to use
- test@mailinator.com - Temporary email, not recommended
- support@microsoft.com - Valid but likely a team inbox
Developer Workflow
User (in Claude Code):
Verify the test emails in my .env.example file
Claude:
I'll read the file and verify any email addresses found.
Found 3 email addresses in .env.example:
- TEST_EMAIL=user@example.com
- ADMIN_EMAIL=admin@company.com
- SUPPORT_EMAIL=help@temp-mail.org
Verification results:
Status user@example.com Unknown (example domain) admin@company.com Valid help@temp-mail.org Invalid (disposable) Consider using real email addresses for testing.
Output Format
The MCP server returns well-formatted results:
## Email Verification Result
**Email:** test@example.com
**Status:** VALID
**Confidence Score:** 95.0%
### Details
| Check | Result |
|-------|--------|
| Deliverable | Yes |
| Valid Format | Yes |
| Valid Domain | Yes |
| Valid MX | Yes |
| Disposable | No |
| Role Address | No |
| Catch-all | No |
| Free Provider | No |
**Credits Used:** 1Best Practices
1. Store API Key Securely
Never hardcode your API key. Use environment variables:
{
"env": {
"EMAILVERIFY_API_KEY": "${EMAILVERIFY_API_KEY}"
}
}2. Use Natural Language
The MCP server understands various phrasings:
- "Verify user@example.com"
- "Is test@company.com a valid email?"
- "Check if this email is deliverable: john@test.com"
- "Can you validate these email addresses for me?"
3. Batch When Possible
For multiple emails, ask Claude to verify them together for efficiency:
"Verify all these emails at once: email1@test.com, email2@test.com, email3@test.com"
Troubleshooting
MCP Server Not Found
If Claude says it can't find the EmailVerify tool:
- Check your configuration file path
- Ensure the JSON is valid
- Restart Claude Desktop completely
- Verify your API key is correct
Rate Limit Errors
If you see rate limit errors:
- Check your remaining credits with "How many credits do I have?"
- Wait a moment and try again
- Consider upgrading your plan for higher limits
Connection Issues
If verification fails:
- Check your internet connection
- Verify your API key is valid
- Try a simple verification first
FAQ
Is my API key secure?
Yes. The API key is stored in your local configuration file and only used by the MCP server running on your machine. It's never sent to third parties.
Which AI clients support MCP?
Any MCP-compatible client works, including Claude Desktop, Claude Code, Cursor, Zed, Cline, and Continue.
What happens when offline?
If the EmailVerify API is unreachable, the tool returns an error message. This doesn't affect Claude's other capabilities.
How do credits work?
Each email verification uses 1 credit. Bulk verifications use 1 credit per email. Check your balance with the check_credits tool.