No2Bounce for ChatGPT

Every marketing team knows the quiet cost of a bad email list: bounced campaigns, wasted sends, and a sender reputation that takes months to repair after one bad blast. Most teams do not catch it until the bounce report lands, and by then the damage is done. The No2Bounce MCP server moves that check earlier, into the conversation where you are already planning your outreach.

MCP, the Model Context Protocol, lets ChatGPT reach outside the conversation and call real external tools on your behalf. ChatGPT connects to those tools as custom connectors, so instead of copying an address into a separate dashboard, you just ask. The No2Bounce connector points ChatGPT at the validation API, and verification becomes part of the conversation instead of a separate chore.

• Single address: a deliverability score out of 100, a status (valid, invalid, risky), and a sub-status explaining‍

why: confirmed mailbox, catch-all domain, role-based address, or likely bounce.

• Bulk lists: up to 10,000 addresses per request, returned as a downloadable CSV.

• Long-running jobs: poll a job by tracking ID and pull results whenever they are ready, useful for auditing an old list or validating before a CRM import. 

• Account status: confirm your API key is active and check your remaining credit balance, so you are never caught mid-campaign. 

Custom connectors sit behind Developer mode, available on Plus, Pro, Business, Enterprise and Education plans in the ChatGPT web app. Open Settings, go to Connectors, open Advanced settings, and switch Developer mode on. On a managed workspace an admin has to allow custom connectors first, under Workspace Settings, Permissions and Roles. 

Then add a new custom connector, point it at the No2Bounce MCP endpoint, and authorise it with the API key from your No2Bounce dashboard. One difference from the desktop clients is worth knowing up front: ChatGPT talks to remote MCP servers over Streamable HTTP or SSE only. It does not spawn local packages, so the hosted endpoint is the route here rather than the npm install used by Claude Desktop, Cursor and Windsurf. 

Endpoint: [NO2BOUNCE_MCP_ENDPOINT] 

Transport: Streamable HTTP 

Auth: API key from https://app.no2bounce.com/api

Once the connector is saved, open a new chat, select it from the composer, and the No2Bounce tools are live for that conversation. You can toggle individual tools on or off per connector, and refresh the connector whenever the server adds new ones. 

From there, it is just conversation. Paste an address, paste a list, or ask about your account, and let ChatGPT check it before you hit send. 

• Get your API key → https://app.no2bounce.com/api

Package Info

• View on npmx : https://npmx.dev/package/no2bounce-mcp
• Published by no2bounce-com on npm : https://www.npmjs.com/~no2bounce-com