Instantly email verification
Clean Instantly lists before sending
Verify cold email lists before they reach Instantly campaigns. Verifly helps teams catch risky addresses first, then import cleaner prospects into their sending workflow.
curl -X POST "https://verifly.email/api/v1/verify/batch" \
-H "Authorization: Bearer vf_your_api_key" \
-H "Content-Type: application/json" \
-d '{"emails":["lead1@example.com","lead2@example.com"]}'Real-time SMTP mailbox checks
Single, batch, and async bulk verification
Disposable, role account, and catch-all detection
Pay-as-you-go credits with no subscription lock-in
Search fit
Built for Instantly email verification workflows
Use Verifly when you need a simple API, predictable pricing, and clean JSON results before emails hit your product, CRM, or campaign tool.
Bounce rate is the number Instantly watches
Instantly.ai is a sending platform, and sending platforms live or die on deliverability. When you upload a lead list and start a campaign, every invalid address that bounces is a signal to mailbox providers that your sending domain isn't careful about who it emails. Instantly's account health warnings and the mailbox providers behind them both key off bounce rate, so a dirty list doesn't just waste a few sends — it can throttle an entire warmed-up sending infrastructure.
The failure mode that catches people out is the mixed list: a batch of leads scraped or bought where most are fine but 8-10% are dead. Push that straight into Instantly and the first day of the campaign spikes your bounce rate before you've had a chance to react. Verifying the list first turns that spike into a non-event.
Verifly is a pre-import gate. You batch-verify the whole list, keep the deliverable rows, hold or drop the risky and catch-all ones, and only then hand a clean CSV to Instantly. Because it's pay-as-you-go, cleaning a list before each campaign doesn't add a recurring bill.
How to verify a list before importing to Instantly
- Assemble your lead list as a CSV with one email column, exactly as you'd upload it to an Instantly campaign.
- Register for a free Verifly key at verifly.email/api/v1/autonomous/register (100 credits, no card).
- POST the whole column to /verify/batch in one request. For campaign-sized lists the async bulk pipeline scales to 1M addresses.
- Filter the response: keep result === 'deliverable', and drop anything flagged disposable or role. Treat catch_all as risky and decide per campaign.
- Upload only the cleaned list to Instantly, then let your normal warmup and sending schedule run against addresses that will actually accept mail.
curl -X POST "https://verifly.email/api/v1/verify/batch" \
-H "Authorization: Bearer vf_your_api_key" \
-H "Content-Type: application/json" \
-d '{
"emails": [
"founder@startup.io",
"sales@bigco.com",
"throwaway@mailinator.com"
]
}'
# throwaway@mailinator.com comes back disposable:true -> drop before importFAQ
Frequently asked questions
Doesn't Instantly verify emails on import?
Instantly focuses on sending, warmup, and inbox rotation, not deep mailbox validation. Running a dedicated SMTP verification pass with Verifly before import is what keeps bounce-driven account health warnings from ever triggering.
What bounce rate should I be aiming for?
Keeping hard bounces under roughly 2% is the practical target for protecting a warmed sending domain. Pre-verifying the list is the most reliable way to stay under that line on a cold list you didn't build yourself.
Should I drop catch-all addresses before Instantly?
Catch-all domains accept everything, so Verifly can't confirm the specific mailbox. On a fresh sending infrastructure many teams hold catch-alls back; on an established one with tolerance to spare, they send but watch the bounce report.
Can I verify a large bought list at once?
Yes. The async bulk pipeline handles up to 1,000,000 addresses in a single job, so even a big purchased or scraped list can be cleaned before its first campaign.
How much does pre-import verification cost?
It's pay-as-you-go from $2 per 1,000 checks down to $0.60 per 1,000 at volume, with 100 free credits. Cleaning a list before each Instantly campaign doesn't require a subscription.
Will disposable domains actually be flagged?
Yes. Every result includes a disposable flag, so mailinator-style throwaways and known temp-mail domains are caught and can be stripped before they ever bounce inside Instantly.