Verify Leads Before Sending in Instantly.ai.
Protect Your Warmup Domains.
Importing unverified B2B lists directly into Instantly burns weeks of inbox warmup in a single afternoon. Scrub your CSV exports or automate pre-send API verification with MailVeri to isolate VALID mailboxes and cut verification costs by up to 90%.
Why Raw Lead Lists Destroy Instantly.ai Deliverability
Inbox warmup builds baseline sender reputation, but it cannot override a 6% hard bounce spike on a live campaign.
The 2% Provider Ceiling
Google Workspace and Microsoft 365 monitor outbound NDR (Non-Delivery Report) ratios per sending domain. Exceeding a 2% bounce rate routes cold emails straight to the spam folder across all mailboxes on that domain.
Catch-All Deferred Bounces
Over 30% of B2B domains operate as catch-all servers that accept every recipient during an initial check and send a delayed bounce hours later. MailVeri flags CATCH_ALL domains so you never mix them into primary campaigns.
Full Inbox & Role Filtering
Abandoned mailboxes that exceed storage quotas (FULL_INBOX) and shared group aliases (ROLE_ACCOUNT) hurt reply rates and trigger spam complaints. MailVeri isolates both automatically.
Two Ways to Verify Leads for Instantly.ai
Clean bulk CSV lists before campaign upload or gate your automated lead pipelines in real time via API.
Workflow A: Pre-Import Bulk CSV Cleaning (Zero Code)
Best for SDR teams and agencies importing leads from Apollo, Sales Navigator, or Clay CSV exports
Upload Raw CSV
Upload your raw prospect CSV into the MailVeri Dashboard. All custom personalization columns (First Name, Icebreaker, Company) stay intact.
Export Deliverable Segment
Download the filtered CSV containing strictly VALID contacts for your primary warmup domains.
Import to Instantly
In Instantly.ai, open Campaigns → Leads → Import CSV, map your fields, and enable Check for duplicates across workspace.
Before calling Instantly's POST /api/v2/leads endpoint, verify each prospect via MailVeri's real-time API and only push contacts that return status === "VALID":
POST https://api.mailveri.com/v1/verify-mail/
Authorization: Bearer YOUR_MAILVERI_API_KEY
Content-Type: application/json
{
"email": "[email protected]"
}{
"error": 0,
"message": "Verified [email protected] successfully",
"status": "VALID",
"email": "[email protected]",
"mail": "[email protected]",
"is_disposable": false,
"is_role_account": false,
"is_catch_all": false,
"is_full_inbox": false,
"balance": 49990
}POST https://api.instantly.ai/api/v2/leads
Authorization: Bearer YOUR_INSTANTLY_API_KEY
Content-Type: application/json
{
"campaign": "INSTANTLY_CAMPAIGN_UUID",
"email": "[email protected]",
"first_name": "Jordan",
"last_name": "Taylor",
"company_name": "ScaleOps",
"skip_if_in_workspace": true
}Instantly List Verification Cost Comparison
Stop paying steep markups on bundled verification credits. Compare MailVeri's pay-as-you-go rates for 100,000 cold email leads:
| Provider | Cost per 100K Leads | Cost per 1M Leads | Credit Expiration |
|---|---|---|---|
| MailVeri (Bulk CSV & API) | $59 | $299 | NEVER Expire (Lifetime) |
| Bundled Sequencer Verification | $200 – $250 | $1,500+ | Tied to Monthly Plan |
| NeverBounce | $400 | $3,000 | Expires in 12 Months |
| ZeroBounce | $649 | $3,199 | Expires in 2 Years |
Related Guides for Instantly.ai Senders
How to Verify Emails Before Sending in Instantly & Smartlead (Keep Bounce Rate Under 1.5%)
Learn the 3-tier lead routing matrix for VALID, CATCH_ALL, and FULL_INBOX segments.
Why Apollo “Verified” Emails Still Bounce (And How to Fix It)
Why cached B2B database badges still produce 8%–18% hard bounces on cold campaigns.
How to Verify Emails in Clay Using HTTP API: Save 80% on Waterfall Credits
Verify Clay waterfall leads for 0 Clay credits before pushing to Instantly.ai.
Frequently Asked Questions
Common questions about cleaning lead lists for Instantly.ai cold email campaigns.
What bounce rate should I target in Instantly.ai?
Keep your campaign bounce rate strictly below 1.5% (and never above Google Workspace and Microsoft 365's 2% enforcement ceiling). Importing only MailVeri VALID contacts keeps typical cold outreach bounce rates between 0.4% and 1.2%.
Should I import Catch-All emails into Instantly?
Never mix CATCH_ALL addresses into your primary warmup domains. If you choose to contact high-value catch-all prospects, isolate them into a dedicated secondary domain pool capped at 15–20 emails per day per inbox.
Does MailVeri preserve custom CSV columns like AI icebreakers?
Yes. When you upload a CSV to MailVeri, every original column (First Name, Company, Website, Custom Variables, AI Icebreakers) is 100% preserved and appended with MailVeri's verification status columns.
Ready to protect your Instantly.ai domains?
Sign up in 30 seconds and get 1,000 free verification credits to clean your next Instantly campaign list.