Mailcheck integration

Overview

Mailcheck is an email verification service that checks the deliverability, trust score and quality of an email address. This tool calls the Mailcheck.co API to validate one email address per input item and returns what the service knows about it: a trust rating, whether the address belongs to a disposable provider, whether the domain has MX records, whether the SMTP server accepts the address, whether the domain is catch-all, and any accounts associated with the address.

Node Type

Action — processes input items and produces output

Input / Output

Direction	Port(s)
Input	Input
Output	Output, Error

Credentials

This tool requires Mailcheck API credentials. See the Credentials Guide for setup instructions.

Resources

Resource	Value
Email	email

Operations

Operation	Value	Description
Check	check	Check the deliverability and trust score of an email address.

Parameters

Parameter	Type	Required	Default	Description
Email	string	Yes	—	The email address to verify. Supports expressions like {{ $json.email }}.
Max Concurrency	number	No	10	Maximum number of items to process concurrently.

Output Data

One output item per input item. The verification result is merged onto the input item JSON — the fields the API returns are added at the top level of the item alongside everything that was already there, so upstream fields survive. Binary data on the input item is forwarded unchanged. No operation on this node fans out into multiple items.

The merged fields come from the Mailcheck.co response and cover:

• the trust rating for the address,
• whether the address is disposable (a throwaway provider),
• whether the domain publishes MX records,
• whether the SMTP server accepts mail for the address,
• whether the domain is catch-all,
• any associated accounts the service has seen for the address.

Because the response is merged rather than nested, reference the fields directly downstream — for example {{ $json.trust }} — using the field names shown when you run the node once with a real address.

Example Configuration

Verify a fixed address:

{
  "type": "mailcheck",
  "parameters": {
    "resource": "email",
    "operation": "check",
    "email": "user@example.com"
  }
}

Verify the address carried on each incoming item:

{
  "type": "mailcheck",
  "parameters": {
    "resource": "email",
    "operation": "check",
    "email": "{{ $json.email }}"
  }
}

Verify a large list, with concurrency turned down to stay inside your API rate limit:

{
  "type": "mailcheck",
  "parameters": {
    "resource": "email",
    "operation": "check",
    "email": "{{ $json.contact.emailAddress }}",
    "maxConcurrency": 5
  }
}

Error Handling

Mode	Behavior
stop	Halts workflow on first error
continue	Skips failed items, passes successful ones through
errorPort	Routes failed items to Error output port

Tips

This tool checks the deliverability and trust score of an email address. It is ideal when you need to validate a single email address for quality and risk, rather than performing bulk checks or sending emails. The tool produces a detailed report on the email’s deliverability, trust rating, and other relevant quality indicators.

• One API call is made per input item, so a list of 500 addresses costs 500 calls. Use Max Concurrency to keep the request rate within your plan’s limit.
• An address that fails verification is not an error — the node still returns a result describing why. A failed item on the Error port means the API call itself failed (bad credentials, rate limit, network), not that the address is invalid.
• Filter on the returned trust and disposable fields with a Switch or Filter node to split good addresses from the rest before sending mail.