SMTPing Email Verification

io.github.smtpingPublished by GitHub account smtpingv1.0.1Updated Nov 2, 2026

Verify email addresses, clean lists and check spamtrap, disposable, spambot and complainer lists.

VerifiedStreamable HTTPWeb executableCommunication & CollaborationBusiness & Commerce

Overview

AI-generated overview

SMTPing's official MCP server lets an assistant verify email addresses, clean lists and check threat lists, using paid SMTPing credits.

What you can do
  • Verify a single address and get a status plus a safe/avoid/judgement band
  • Verify a list as one bulk job of up to 100,000 deduplicated addresses and wait for results
  • Check the progress and results of a running bulk job
  • Look up an address in one threat list: spamtrap, disposable, spambot or complainer
  • Check the remaining credit balance and plan
When to use it
Useful when an assistant works with lead lists, signup forms or outreach data and you want addresses checked for validity, catch-all, disposable or spamtrap status before sending. Also handy for cleaning a pasted list in a conversation and reporting which addresses are safe to email.
Requirements
A SMTPing account and API key, supplied as the SMTPING_API_KEY environment variable for the local npm package or via OAuth sign-in for the remote endpoint. The local package needs Node 18 or later; the remote server needs no install. Network access to the SMTPing API.
Before you install
Verification spends SMTPing credits: 1 per single address, 1 per unique address in a bulk list, and 1 per threat lookup, so large lists can consume many credits. The API key is a secret and should be kept out of shared config files. Email addresses are sent to the SMTPing API whenever a tool is called.

Installation

In SourceWeft

  1. Open SMTPing Email Verification in the dashboard and add it to a workspace.
  2. Connect the required credentials. They are stored privately and never shown on public pages.
  3. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.github.smtping%2Fsmtping-mcp/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config. The client completes OAuth sign-in on first connect.

{
  "mcpServers": {
    "smtping-email-verification": {
      "type": "http",
      "url": "https://mcp.smtping.com/mcp"
    }
  }
}

README

SMTPing MCP server

Official Model Context Protocol server for SMTPing. It lets Claude, Cursor, VS Code, Windsurf and any MCP client verify email addresses in a conversation.

"Verify these 40 leads and tell me which ones are safe to email."

Remote server (no install)

Prefer not to run Node? Add https://mcp.smtping.com/mcp as a custom connector in Claude (Settings > Connectors) or ChatGPT, then sign in with your SMTPing API key. Same 5 tools, OAuth 2.1, nothing stored on the server. Source: smtping/smtping-mcp-remote.

Tools

toolwhat it doescredits
verify_emailVerifies one address: status plus band (safe, avoid, judgement)1
verify_listVerifies a list as one bulk job (up to 100,000), waits for results1 per unique address
get_bulk_jobProgress and results of a bulk job0
check_threatLooks up one address in the spamtrap, disposable, spambot or complainer list1
get_creditsRemaining credits and plan0

Setup

Create an API key in the SMTPing dashboard, then add the server to your client. Node 18 or later is required.

Claude Desktop

Settings > Developer > Edit Config, then add to claude_desktop_config.json:

json
{  "mcpServers": {    "smtping": {      "command": "npx",      "args": ["-y", "@smtping/mcp"],      "env": { "SMTPING_API_KEY": "sk_live_your_key_here" }    }  }}

Restart Claude Desktop.

Claude Code

bash
claude mcp add smtping -e SMTPING_API_KEY=sk_live_your_key_here -- npx -y @smtping/mcp

Cursor

~/.cursor/mcp.json (or .cursor/mcp.json in a project): same JSON block as Claude Desktop.

VS Code

.vscode/mcp.json:

json
{  "servers": {    "smtping": {      "command": "npx",      "args": ["-y", "@smtping/mcp"],      "env": { "SMTPING_API_KEY": "sk_live_your_key_here" }    }  }}

Windows troubleshooting

npx is not found: use "command": "cmd" and "args": ["/c", "npx", "-y", "@smtping/mcp"].

"Request timed out" or "Server disconnected" on first start: the first npx run downloads the package and can take longer than the client's 60 second startup limit. Install the server once, then point the client to it:

  1. In a terminal: npm install -g @smtping/mcp
  2. Replace the smtping block with:
json
"smtping": {  "command": "node",  "args": ["C:\\Users\\YOUR_NAME\\AppData\\Roaming\\npm\\node_modules\\@smtping\\mcp\\index.js"],  "env": { "SMTPING_API_KEY": "sk_live_your_key_here" }}

Replace YOUR_NAME with your Windows user folder (spaces are fine) and use double backslashes. Run echo %APPDATA% to see the exact path. This form also avoids issues with .cmd launchers when the user folder contains a space.

  1. Quit the client completely (tray icon > Quit) and reopen it.

To update later: npm install -g @smtping/mcp@latest.

Logs: Claude Desktop writes them to %APPDATA%\Claude\logs\mcp-server-smtping.log.

Privacy

Addresses are sent to the SMTPing API only when a tool is called. See the privacy policy.

Links

MIT License

Source: README.md at commit aa241f3

Tools

5

verify_email

Verify an email address

Verifies one email address with SMTPing. Returns a status (valid, invalid, catch_all, spamtrap, disposable, etc.) and a band: safe (send), avoid (remove) or judgement (your call). Costs 1 credit.

Parametersemailrequired

verify_list

Verify a list of email addresses

Verifies a list of addresses as one SMTPing bulk job (deduplicated, up to 100,000). Waits up to 120 seconds; if the job is still running, returns a job_id to pass to get_bulk_job later. Costs 1 credit per unique address.

Parametersemailsrequiredwait_seconds

get_bulk_job

Get a bulk job

Returns the progress of a SMTPing bulk job, and its results once it has succeeded.

Parametersjob_idrequired

check_threat

Check a threat list

Looks up one address in a single SMTPing threat list: spamtrap, disposable, spambot or complainer.

Parameterslistrequiredemailrequired

get_credits

Get remaining credits

Returns the remaining SMTPing credit balance and plan. Free.

Takes no parameters.

Version history

2
  1. v1.0.1LatestOct 26, 2026
  2. v1.0.0Sep 27, 2026

Score

100% of the applicable checks met

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  • License10 pts