Lemlist email verification with BillionVerify
Lemlist is a sales engagement platform built for cold email and multichannel outreach. Teams use it to send personalized email sequences, automate follow-ups, and track reply rates. Clean, deliverable email lists are essential — bounced messages damage sender scores and reduce campaign reach.
Why verify before the send
Cold outreach lives and dies by sender reputation. Sending to invalid, disposable, or role-based addresses in Lemlist triggers bounces that ISPs use to flag your domain as spam. Running lists through BillionVerify before import ensures only reachable, non-toxic contacts enter your sequences, protecting deliverability and open rates.
Ready-to-use n8n workflow
Import this workflow into n8n — it verifies every address with BillionVerify before Lemlist sends, so only deliverable contacts are emailed. Install the BillionVerify community node first, then add your API key.
{
"name": "Verify emails before sending in Lemlist + 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 Lemlist contacts",
"message": "Replace this Gmail send with your Lemlist 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 Lemlist
Ready-to-use workflows that verify emails before Lemlist sends.
How it works
- 1
Connect BillionVerify to your workflow using the n8n community node, Integrately 1-click integration, or the REST API.
- 2
Trigger verification whenever a new lead is added to Lemlist or before a campaign is launched.
- 3
BillionVerify checks each address for validity, disposable domains, role accounts, and catch-all status.
- 4
Contacts that pass verification are kept in or added to the Lemlist campaign; invalid ones are flagged or removed.
- 5
Monitor verification results over time to catch new sources of low-quality emails early.
When to use this
Pre-campaign list hygiene
Before uploading a prospect list to Lemlist, pipe it through BillionVerify via n8n or Integrately to strip invalid, catch-all, and disposable addresses. Start every campaign with a verified, high-quality audience.
Lead enrichment validation
When new leads arrive from forms, scrapers, or CRM exports, verify each email in real time before adding it to a Lemlist campaign step. Prevent unverified contacts from ever entering an active sequence.
Bounce rate recovery
If a previous campaign generated high bounces, export the contact list, run it through BillionVerify, and re-import only the verified addresses to resume outreach on a clean slate.
FAQ
Why does email verification matter specifically for cold outreach tools like Lemlist?
Cold email domains have less established reputation, making them more vulnerable to bounce-triggered spam filters. Keeping bounce rates under 2% is critical, and verification ensures every address you contact is reachable.
Can I verify emails in bulk before importing a CSV to Lemlist?
Yes. Use BillionVerify's REST API or n8n node to process a list of addresses in bulk, then filter out invalid results before uploading the cleaned CSV to Lemlist.
What types of addresses does BillionVerify catch?
It detects invalid syntax, non-existent mailboxes, disposable email services, role addresses like info@ or admin@, and catch-all domains that accept any email regardless of whether the mailbox exists.
Does verification slow down my outreach workflow?
BillionVerify processes addresses quickly via its API. For large lists, bulk verification can run asynchronously in n8n before a campaign starts, adding minimal time to your setup process.
Verify emails in Lemlist
Create a free account, grab your API key, and stop bounces before they happen.
Get started free