Mailshake email verification with BillionVerify
Mailshake is a sales engagement platform built for cold outreach — sequences, follow-ups, and reply detection at scale. Because cold outreach sends mail to unverified prospects, email validation is essential: BillionVerify eliminates bad addresses before they ever enter a Mailshake campaign and damage your sending reputation.
Why verify before the send
Cold outreach lists are particularly prone to stale, invalid, and role-based addresses from scraped or purchased sources. High bounce rates in Mailshake campaigns trigger ESP throttling, domain blacklisting, and reduced inbox placement for every future send. Verifying addresses with BillionVerify before import is the single most effective step to protect deliverability.
Ready-to-use n8n workflow
Import this workflow into n8n — it verifies every address with BillionVerify before Mailshake sends, so only deliverable contacts are emailed. Install the BillionVerify community node first, then add your API key.
{
"name": "Verify emails before sending in Mailshake + 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 Mailshake contacts",
"message": "Replace this Gmail send with your Mailshake 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 Mailshake
Ready-to-use workflows that verify emails before Mailshake sends.
How it works
- 1
Export your prospect list or connect your lead source to an n8n workflow.
- 2
Run each email address through the BillionVerify node for deliverability and type classification.
- 3
Filter out invalid, disposable, and role-based addresses from the verified results.
- 4
Import only clean, verified contacts into Mailshake as campaign recipients.
- 5
Re-verify lists periodically as email addresses degrade over time, especially for evergreen sequences.
When to use this
Screen Prospect Lists Before Campaign Launch
Pass every prospect email through BillionVerify before adding contacts to a Mailshake campaign. Remove invalid and disposable addresses, reducing bounce rates to levels that keep sending domains healthy.
Validate Inbound Leads Added to Sequences
When new leads arrive from forms or enrichment tools and are automatically enrolled in Mailshake sequences, BillionVerify verifies each address first — preventing undeliverable contacts from polluting active campaigns.
Flag Catch-All Domains for Separate Treatment
BillionVerify identifies catch-all domains that accept all mail at the server level but may silently discard it. Segment these contacts for lower-frequency follow-ups to protect sender reputation.
FAQ
How much can email verification reduce bounce rates in cold outreach?
Teams that verify before sending typically reduce hard bounces by over 90%, keeping bounce rates well below the thresholds that trigger ESP warnings or sending suspensions.
Should I verify addresses even if I bought a list from a reputable vendor?
Yes. Even high-quality purchased lists degrade at roughly 20–30% per year. Verifying before import catches stale addresses and avoids domain reputation damage regardless of list source.
What is the difference between invalid and catch-all addresses?
Invalid addresses return a hard bounce. Catch-all addresses accept mail at the server level but may silently discard it. BillionVerify distinguishes the two so you can apply different sending strategies to each group.
Can BillionVerify integrate with Mailshake without n8n?
Yes. Integrately offers a 1-click connection, and the BillionVerify REST API can be called from any script or automation tool that can make HTTP requests.
Verify emails in Mailshake
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