This MCP server exposes a find_work_email tool for finding, verifying, and cost-attributing work emails for contacts using your own provider API keys.
Accepts one or more contacts with identifiers such as name, company domain/name, LinkedIn URL, or email.
Runs a configurable chain of finder providers using your own providerKeys, validating keys for free before paid calls and dropping unusable providers.
Verifies addresses after each finder that returns one, rather than only at the end.
Returns flat, Clay-ready rows for every contact, including misses, plus a summary row with run totals.
Reports provider attribution, units spent, and optional dollar costs via providerRates.
Supports caps and controls: maxContacts, maxProviderUnits, max_charge_usd, providerOrder, verificationOrder, and concurrencyHint.
Completes even with no usable keys, explains unavailable capabilities, and charges nothing in that case.
Requires APIFY_TOKEN and consumes Apify credits per contact submitted and per address found, separate from your provider spend.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@Work Email Waterfall MCP Server Find and verify work emails for this list of contacts with my provider keys"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
MCP server for the Mamba Labs Work Email Waterfall actor on Apify.
Give it contacts and your own provider API keys. It finds a work email for each, verifies it, and tells you exactly what each provider cost you.
find_work_email
Returns one flat row per contact, misses included, plus a summary row carrying the run totals: the address found, which provider found it, its position in the chain, every provider attempted, the verification verdict and its source, and the provider units spent.
Related MCP server: Waterfall Enrichment Orchestrator
This is the part that makes it different from a credit-based enrichment tool. Mamba Labs supplies no provider keys, never sees your credits, and never resells them. The run spends from your accounts at your negotiated rates, which is why maxProviderUnits exists and why you should set it.
The tradeoff is honest in both directions: you keep your own pricing and your own provider relationships, and you carry your own spend. What you get back is real attribution rather than a credit count, so you can see which provider actually earned its keep.
Give it providerRates and the run reports dollars at your rate. Leave it empty and it reports units only, because your plan tier is not knowable from here and guessing it would produce a confident wrong number.
Nothing dramatic. Every key is validated for free before any paid call. A provider with no usable key is dropped from the chain and reported, rather than failing the run or silently burning attempts. With no keys at all the run still completes, explains which capabilities were unavailable, and charges nothing.
Verification runs after each finder that returns an address, not once at the end, because providers do not agree on what "found" means. An address that one provider calls a hit and a verifier calls undeliverable is a miss, and you want to know that before it reaches a sequencer.
find_work_emailInput | Type | Notes |
| object[] | One object per person. Any of |
| object | Your own keys, by provider name. Validated for free before any paid call. |
| string[] | Registry entry ids in call order. Empty means the actor's default chain. |
| string[] | Verifier entry ids in order. Empty means the actor's default. |
| integer | Hard ceiling on contacts processed. |
| integer | Run-level cap on provider credits spent from your accounts. Strongly recommended. |
| object | Map of provider or provider.endpoint to your cost per unit, so spend is reported in dollars. |
| integer | Advisory. Real pacing comes from each endpoint's own multi-window rate limits. |
| number | Optional cost cap in USD for this run. The actor stops before an item that could take its charges past this amount. |
More identifiers means a better chance of a hit. Keyed on a LinkedIn URL the top provider measured 13.7 percent against 9.3 percent on name plus domain, on the same 300 contacts in the same hour.
{
"mcpServers": {
"mamba-email-waterfall-orchestrator": {
"command": "npx",
"args": ["-y", "@mambalabsdev/mcp-email-waterfall-orchestrator"],
"env": { "APIFY_TOKEN": "your-apify-token" }
}
}
}Get a token at console.apify.com/account/integrations. Each call spends from your own provider accounts and consumes Apify credits per contact submitted and per address found, on top of whatever your own provider keys spend.
Price per event on the Apify FREE plan, from the live pricing record; paid Apify plans pay less per event.
Event | Price (USD) |
Actor Start ( | 0.00005 |
Email Search Submitted ( | 0.003 |
Email Found ( | 0.02 |
This tool is also exposed by the GTM Suite umbrella server, alongside the rest of the Mamba Labs GTM actors, if you would rather run one server than many.
Built by Mamba Labs.
Find a work email address for each contact by running a chain of finder providers on YOUR OWN provider API keys, verify each result, and return real per-provider spend attribution instead of an opaque credit count. This is bring your own key: Mamba Labs supplies no provider keys, never sees your credits, and the run spends from your accounts, so set maxProviderUnits. Supply contacts as an array of objects, each carrying any of full_name, first_name, last_name, company_domain, company_name, linkedin_url and email. More identifiers means a better chance of a hit. Supply your keys in providerKeys by provider name. Every key is validated for free before any paid call, and a provider with no usable key is dropped from the chain and reported rather than failing the run; with no keys at all the run still completes, explains what was unavailable and charges nothing. Verification runs after each finder that returns an address, not once at the end. Every contact gets a row including misses, so you can see what was attempted, and a final summary row carries the run totals and spend. Returns flat Clay-ready JSON. Requires an APIFY_TOKEN and consumes Apify credits per contact submitted and per address found, on top of whatever your own provider keys spend.
Inputs: contacts (required), maxContacts, providerKeys, providerOrder, +4 more.
Recent tool additions, removals, and schema changes observed during successful MCP inspections.
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Scored across 1 tool
With only one tool, there is no possibility of confusing it with another. The tool's purpose is clearly defined and distinct.
The tool name 'find_work_email' follows a clean verb_noun pattern. While consistency is trivially met with a single tool, the name is descriptive and predictable.
A single-tool server feels thin, but for this niche operation (finding work emails via provider chaining) it may suffice. However, separate tools for key management or provider configuration would improve structure.
The tool covers the full workflow: accepting multiple contact identifiers, running providers, verifying results, handling missing keys, providing per-contact and summary rows, and returning JSON. No obvious gaps exist within its stated scope.
Find and verify B2B work emails, single or bulk. OAuth sign-in or API key; pay per verified email.
Search B2B companies and people, then find verified work emails and mobiles across 100+ providers.
Find and verify work emails with live SMTP checks and catch-all detection. Free 10 calls/day.
Find and verify work emails by name, company, role or LinkedIn URL, and find who is behind an email.
