Formdesk email verification with BillionVerify
Formdesk is an online form platform popular in the Netherlands for building structured data collection forms. Adding BillionVerify to your Formdesk workflow means email addresses are validated the moment someone submits a form, so your records stay accurate from day one.
Why verify before the send
Forms collect data from a wide audience, and not every submitter provides a genuine email. Invalid syntax, temporary inboxes, and catch-all domains are common pitfalls. Verifying at submission time with BillionVerify prevents undeliverable addresses from entering your system and affecting your email channel's performance.
Ready-to-use n8n workflow
Import this workflow into n8n — it verifies every address with BillionVerify before Formdesk sends, so only deliverable contacts are emailed. Install the BillionVerify community node first, then add your API key.
{
"name": "Verify emails before sending in Formdesk + BillionVerify",
"nodes": [
{
"parameters": {},
"type": "n8n-nodes-base.manualTrigger",
"typeVersion": 1,
"position": [
240,
300
],
"name": "When clicking ‘Test workflow’"
},
{
"parameters": {
"assignments": {
"assignments": [
{
"id": "email-field",
"name": "email",
"value": "jane@example.com",
"type": "string"
}
]
},
"options": {}
},
"type": "n8n-nodes-base.set",
"typeVersion": 3.4,
"position": [
460,
300
],
"name": "Get contacts"
},
{
"parameters": {
"sendTo": "={{ $json.email }}",
"subject": "Message for Formdesk contacts",
"message": "Replace this Gmail send with your Formdesk node — only deliverable, verified contacts reach it.",
"options": {}
},
"type": "n8n-nodes-base.gmail",
"typeVersion": 2.1,
"position": [
900,
300
],
"name": "Send email",
"webhookId": "",
"credentials": {
"gmailOAuth2": {
"id": "",
"name": "Gmail account"
}
}
},
{
"parameters": {
"operation": "verify",
"email": "={{ $json.email }}",
"additionalOptions": {}
},
"type": "n8n-nodes-billionverify.billionVerify",
"typeVersion": 1,
"position": [
540,
300
],
"name": "Verify Email (BillionVerify)",
"credentials": {
"billionVerifyApi": {
"id": "",
"name": "BillionVerify account"
}
}
},
{
"parameters": {
"conditions": {
"options": {
"caseSensitive": true,
"leftValue": "",
"typeValidation": "loose"
},
"combinator": "and",
"conditions": [
{
"id": "is-deliverable",
"leftValue": "={{ $json.is_deliverable }}",
"rightValue": "",
"operator": {
"type": "boolean",
"operation": "true",
"singleValue": true
}
}
]
}
},
"type": "n8n-nodes-base.if",
"typeVersion": 2,
"position": [
720,
300
],
"name": "IF deliverable"
}
],
"connections": {
"When clicking ‘Test workflow’": {
"main": [
[
{
"node": "Get contacts",
"type": "main",
"index": 0
}
]
]
},
"Get contacts": {
"main": [
[
{
"node": "Verify Email (BillionVerify)",
"type": "main",
"index": 0
}
]
]
},
"Verify Email (BillionVerify)": {
"main": [
[
{
"node": "IF deliverable",
"type": "main",
"index": 0
}
]
]
},
"IF deliverable": {
"main": [
[
{
"node": "Send email",
"type": "main",
"index": 0
}
],
[]
]
}
},
"settings": {
"executionOrder": "v1"
}
}Workflow templates with Formdesk
Ready-to-use workflows that verify emails before Formdesk sends.
How it works
- 1
A respondent submits a Formdesk form containing an email field.
- 2
Formdesk sends the submission data to your automation layer — n8n, Integrately, or a direct API call.
- 3
BillionVerify evaluates the address for validity, deliverability, and risk factors such as disposable or catch-all domains.
- 4
The result is returned and used to route the submission: valid emails go to your database, problematic ones are quarantined.
- 5
Your team engages only with contacts who have real, working email addresses.
When to use this
Membership and registration forms
When users register through a Formdesk form, BillionVerify confirms their email is real and reachable before the account is created, reducing fake registrations and wasted onboarding emails.
Customer feedback collection
Feedback forms often include email fields for follow-up. Verifying these addresses ensures your support or customer success team can actually reach respondents who request a reply.
FAQ
Does BillionVerify work with Formdesk webhooks?
Yes. Configure a Formdesk webhook to fire on submission, then pass the email field to BillionVerify via n8n, Integrately, or a direct REST API call.
What does a catch-all email verdict mean?
A catch-all domain accepts all incoming email regardless of whether the specific address exists, making deliverability uncertain. BillionVerify flags these so you can decide how to handle them.
How accurate is the email verification?
BillionVerify uses SMTP-level checks, syntax validation, and domain analysis to achieve high accuracy. Disposable and role-address detection is based on continuously updated lists.
Verify emails in Formdesk
Create a free account, grab your API key, and stop bounces before they happen.
Get started free