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# Keep your Findymail exclusion list up to date

> Add new customers and closed prospects to your Findymail exclusion list on a schedule, so Intellimatch stops returning companies you already know.

Source: https://cotlet.dev/integrations/findymail-api-mcp-server/sync-exclusion-list

Your Intellimatch searches are only as clean as your exclusion list, and the list goes stale the week after a deal closes. Someone has to remember to add the new customers.

Cotlet does it in your own Findymail account with list\_exclusion\_lists, create\_exclusion\_list, list\_excluded\_domains and add\_excluded\_domains, called by your AI agent, an n8n workflow or a script.

[Sign up free](https://cotlet.dev/app/signup?app=findymail) [All Findymail tools](https://cotlet.dev/integrations/findymail-api-mcp-server.md)

Hosted · nothing to install or maintain

## Can Findymail do this on its own?

Findymail's API has exclusion list endpoints that create lists and add or remove domains, up to 10,000 domains per call (checked 23 Oct 2026). It has no MCP server and nothing in its docs reads your customers from a CRM or billing tool for you, so an agent needs a wrapper with your API key.

## How you do it in Findymail today

1. Findymail's Intellimatch page says you can upload a list of companies to exclude, such as current customers or past prospects, and Intellimatch removes them from results automatically.
2. Whoever owns prospecting collects the domains of new customers and closed prospects from the CRM or the billing tool, one source at a time.
3. They add the domains to the exclusion list in Findymail by hand. The page describes the upload but no schedule and no sync from a CRM.
4. A list can be shared with the team, but sharing needs a team plan, so a solo account keeps its lists private.

## How to keep your Findymail exclusion list up to date

Prompt

```
Add the domains of this month's new customers (acme.io, northwind.com, globex.co) to my Customers exclusion list in Findymail. Create the list if it does not exist, and skip domains that are already on it.
```

1. 01  
### Find the list  
Your agent reads your lists with list\_exclusion\_lists and looks for the name in your prompt. Lists shared by your team come back too, with is\_owner telling the agent which ones it may change. A list name is unique per user, so the agent never creates a second Customers list.
2. 02  
### Create it only when missing  
If no list has that name, create\_exclusion\_list makes it, private unless you asked for it to be shared. Sharing fails on an account that is not on a team, and the agent then reports it instead of retrying.
3. 03  
### Skip what is already there  
list\_excluded\_domains with the query filter and the list\_id shows whether a domain is already on the list. The agent drops those from the batch and cleans the rest to bare domains, so acme.io stays acme.io and a pasted https://www.acme.io/pricing becomes acme.io.
4. 04  
### Add the new domains  
add\_excluded\_domains sends the whole batch in one call, up to 10,000 domains. Findymail processes the first 50 at once and queues the rest in the background, so the reply can show fewer processed\_immediately than total. Adding reaches nobody and can be undone, so it does not wait for your OK.
5. 05  
### Report the list  
The agent returns how many domains were sent, how many were already there and the list ID, so you can use the same list in your next Intellimatch search.

### What you get back

Example data

```
Customers list (id 1204): 3 domains sent
Added: acme.io, northwind.com, globex.co
Already on the list: 0
Processed immediately: 3, queued: 0
```

### Other ways to ask

- Every Friday, add the domains of deals marked Closed won this week to my Customers list.
- Create a Competitors list shared with my team and add these 40 domains to it.
- Show me every domain on my Past prospects list that contains "agency", and change nothing.

## What Findymail allows, and what to know first

- Findymail takes up to 10,000 domains per add call, processes the first 50 immediately and queues the rest for background processing.
- An exclusion list name must be unique per user; creating a duplicate returns a 422 error.
- Without a list\_id, domains go to the global exclusion list, which Intellimatch searches use by default.
- Only the owner of a list can rename or delete it, and deleting a list also deletes its domains.
- Removing domains from a shared list needs the removeDomains permission, and removing domains from the global list needs you to own them.

create\_exclusion\_list and add\_excluded\_domains change only your own Findymail data and reach no one else, so they run without asking first.

Sources: [Findymail API documentation: Exclusion Lists](https://app.findymail.com/docs/) · [Findymail Intellimatch, the AI lead finder](https://www.findymail.com/ai-b2b-lead-finder/)

## Call add\_excluded\_domains from a script

curl

```
curl -X POST https://cotlet.dev/api/v1/findymail/excluded-domains \
  -H "Authorization: Bearer $COTLET_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"list_id":1204,"domains":["acme.io","northwind.com","globex.co"]}'
```

Example response

```
{
"success": true,
"total": 3,
"processed_immediately": 3,
"queued": 0,
"list_id": 1204
}
```

MCP: add https://cotlet.dev/mcp/v1 with the same key; the call is findymail\_write → add\_excluded\_domains. Example data.

[Schedule it in n8n, Make, Zapier or cron](https://cotlet.dev/integrations/findymail-api-mcp-server.md#automations)

## Findymail tools this automation uses

__Cotlet Findymail tools used to keep your Findymail exclusion list up to date__
| Tool | Parameters |
| ----------------------- | -------------------------------- |
| list\_exclusion\_lists | none |
| create\_exclusion\_list | name, is\_shared |
| list\_excluded\_domains | list\_id, query, page, per\_page |
| add\_excluded\_domains | domains, list\_id |

[All 14 Findymail tools with descriptions](https://cotlet.dev/integrations/findymail-api-mcp-server.md#tools)

## Frequently asked questions

### What happens to domains over the first 50?

Findymail queues them for background processing. They show up in the list shortly after the call, and the reply tells you how many were processed at once and how many were queued.

### Is it safe to connect Findymail to Cotlet?

Yes. You sign in to Findymail yourself, in your own Cloud Browser in the EU, and we never save your password. Your agents only get Findymail once you enable it, every background request is listed, and the browser profile is stored encrypted with AES-256-GCM, the cipher 1Password uses for its vaults. The AI model never sees a login, posts and messages wait for your OK, and Disable for agents cuts access in one click. Independent scanners grade cotlet.dev A+ on Qualys SSL Labs, securityheaders.com and Mozilla Observatory; live results are on https://cotlet.dev/security.

## More Findymail automations

- [Build a Findymail lead list from your ideal customer](https://cotlet.dev/integrations/findymail-api-mcp-server/build-lead-list-from-icp.md)
- [Findymail API and MCP server: every tool](https://cotlet.dev/integrations/findymail-api-mcp-server.md)
- [All use cases](https://cotlet.dev/use-cases.md)

## Give your agent access to Findymail.

Free 7-day trial with 2,000 credits, no card needed. Cotlet is independent and not affiliated with Findymail.

[Sign up free](https://cotlet.dev/app/signup?app=findymail)

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