Manage Mail Blaze lists, subscribers, templates, campaigns and reports; send transactional email. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the Mail Blaze connector, then ask in plain words. The AI picks the tools.
For marketers and small businesses who send email campaigns with Mail Blaze.
The AI lists your mailing lists with subscriber counts and opens one list for its settings, fields and segments.
The AI reads report summaries of up to 50 campaigns, with sent, opens, clicks, bounces and unsubscribes, and compares them for you.
The AI finds a subscriber by email in a list and reads that person's email activity, with sends, opens, clicks and bounces.
The AI adds one subscriber, or up to 100 in one request, to a mailing list, and updates a subscriber's name or custom fields. The list may send a confirmation email.
Changes dataThe AI unsubscribes a subscriber who asked to stop, or resubscribes someone who asked to be added back.
Changes dataThe AI schedules a campaign from a template to a list or segment, or sends one email to one recipient. Both leave once sent and cannot be recalled.
Changes dataThe login page asks for your Mail Blaze API public key.
Find it in Mail Blaze → your Profile menu → API Keys: create a key and copy the Public key. The key acts with full access to your account; you can revoke it there at any time. Your key is used only to call the Mail Blaze API on your behalf; it is never shown to anyone.
Team and Enterprise: an Owner adds the connector for the organization first.
No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"mailblaze": {
"url": "https://mailblaze.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"mailblaze": {
"type": "http",
"url": "https://mailblaze.usefulapi.io/mcp"
}
}
} Run these commands. The second one opens the login page:
Windsurf, Cline, Zed and other MCP clients: add this URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Mail Blaze API public key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper API key | $9/mo · $90/yr | 10,000 tool calls / month |
| Pro+per API key | $39/mo · $390/yr | 100,000 tool calls / month |
Each paid plan covers this Mail Blaze server only. Ask your AI to run mailblaze_upgrade and choose Pro or Pro+, billed monthly or yearly (it returns a Stripe Checkout link). If you already have Pro, ask to change it to Pro+. The change requires your confirmation, keeps your billing interval and charges the price difference for the rest of the period immediately. Cancel any time with mailblaze_cancel_subscription: your paid plan continues to the end of the paid period, with no refund for the current period, and asking to resume the same plan with mailblaze_upgrade before then undoes the cancel. Or write to [email protected].
mailblaze_list_listsmailblaze_get_listmailblaze_list_list_fieldsmailblaze_list_segmentsmailblaze_list_subscribersmailblaze_get_subscribermailblaze_find_subscriber_by_emailmailblaze_list_templatesmailblaze_get_templatemailblaze_list_campaignsmailblaze_get_campaignmailblaze_get_campaign_summariesmailblaze_get_campaign_inbox_breakdownmailblaze_list_campaign_eventsmailblaze_get_subscriber_activitymailblaze_get_report_jobmailblaze_list_transactional_emailsmailblaze_get_transactional_emailmailblaze_add_subscribermailblaze_add_subscribers_bulkmailblaze_update_subscribermailblaze_unsubscribe_subscribermailblaze_resubscribe_subscribermailblaze_create_templatemailblaze_create_campaignmailblaze_send_transactional_emailmailblaze_usage_statusmailblaze_request_featuremailblaze_upgrademailblaze_cancel_subscriptionCount subscribers on each mailing list. Compare opens, clicks and bounces of campaigns. Check if an address is subscribed and what it opened. Add subscribers or update their details. Unsubscribe or resubscribe a person. Schedule a campaign or send a transactional email. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by Mail Blaze. The server calls the Mail Blaze API with your own Mail Blaze access, so it sees only the data that your account can see.
Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.
The login page asks for your Mail Blaze API public key. See Before you connect for where to find it.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your Mail Blaze API public key. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the Mail Blaze API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in Mail Blaze.
Yes, if you approve it. 8 of the 26 Mail Blaze tools can create or change data. The other 18 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with 10,000 tool calls / month. Pro+ costs $39/mo or $390/yr, with 100,000 tool calls / month. Each subscription covers this Mail Blaze server only. Cancel any time: your paid plan then runs to the end of the paid period. Run mailblaze_usage_status to see how many calls you used.
Ask the AI to run mailblaze_upgrade and choose Pro or Pro+, billed monthly or yearly: it returns a Stripe Checkout link. If you already have Pro, ask to change it to Pro+. After you confirm, your existing subscription changes in place, keeps its billing interval and charges the price difference for the rest of the period immediately. To cancel, run mailblaze_cancel_subscription. Your paid plan continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with mailblaze_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.
Need a tool this server does not have, or a connection to another system? We build custom integrations and MCP servers.