bolt Mailsfinder + Instantly

Verify cold outreach lists before they hit Instantly

Cold lists from Apollo, scrapers, and lead vendors carry 8 to 25% stale addresses. Push that into Instantly and bounce rates above 5% start cooking sender reputation across your connected mailboxes. Mailsfinder runs every list through pre-flight verification via Zapier, Make, or direct API, so only deliverable contacts enter Instantly campaigns. Bounces drop under 1%, inbox placement holds, and your sending IPs stay clean.

Start Free Trial arrow_forward Talk to Sales calendar_month

check_circleBounce rate under 1% check_circle50 free credits, no card check_circleWire up via Zapier or Make

shield

Pre-flight verification

Apollo export, 10,000 leads

Raw rows imported 10,000

Invalid syntax removed 412

Hard bounces flagged 1,083

Catch-all and risky 624

Pushed to Instantly 7,881 verified

Projected bounce rate 0.6%

Verify before send

Trusted by Instantly operators, lead gen agencies, and SDR teams in 40+ countries

Klients Growth Outbound Labs PipelinePro DemandLoop ColdStack SDR Republic

Why Instantly users add Mailsfinder

Three layers of protection before a single Instantly send

Bulk pre-flight, real-time API for live campaigns, and a bounce-rate dashboard that flags risk before it ships.

fact_check

Pre-flight bulk verification

Drop a 50,000-row Apollo export and Mailsfinder runs SMTP probing, MX validation, and catch-all detection on every row. The cleaned CSV imports straight into an Instantly campaign with zero manual scrubbing in between.

bolt

Real-time API for live campaigns

The Verifier API returns a deliverability decision in under 500ms. Wire it into a Zapier or Make webhook so leads added mid-sequence get verified in real time and only deliverable rows enter the active Instantly cadence.

monitoring

Bounce-rate dashboard pre-send

Mailsfinder projects bounce risk before the list ever hits Instantly. See the percentage of deliverable, catch-all, risky, and hard-bounce rows at a glance. Reject lists with risk over 3% before they touch your sending domain.

How it works

From scraped list to deliverable Instantly campaign in four steps

The same workflow whether you run one mailbox or a hundred Instantly workspaces.

Pull list from Apollo or scraper

Export from Apollo, Sales Navigator, Clay, PhantomBuster, or any scraper. Drop it as a CSV or pipe it directly into a Make or Zapier scenario.

Mailsfinder verifies via API

Each row runs through the Verifier endpoint. SMTP probe, MX validation, role detection, catch-all check. Every email returns a status code and risk score.

Filter deliverable only

Auto-drop rows tagged hard_bounce, risky, role, and disposable. Optionally keep catch-all rows in a separate test segment for cautious warming.

Push to Instantly campaign

The cleaned list lands in Instantly as a new lead block. Bounce rate stays under 1%, sender reputation holds, and inbox placement protects across every connected mailbox.

Deep dive

A Make scenario that verifies every lead before Instantly ever sees it

The most common production setup runs five Make modules in sequence. Apollo exports a list, Mailsfinder verifies each row, a filter drops anything that is not deliverable, and Instantly receives the cleaned contacts as a new lead batch. The whole scenario runs unattended on a schedule.

check_circle Module 1, Apollo trigger. Watch for new contacts in a saved search or pull a fresh segment on a daily cron.
check_circle Module 2, Mailsfinder Verify Email. Pass the email field, receive status, risk score, and is_catch_all flag.
check_circle Module 3, Filter. Continue only if status equals deliverable and risk_score is greater than 80.
check_circle Module 4, Instantly Add Lead. Map first_name, last_name, company, and email into the target Instantly campaign.
check_circle Module 5, Google Sheets log. Write verified and rejected counts to a daily QA tracker for sender reputation reviews.

POST /v1/verifier/email

{
  "email": "sarah.chen@acme.io",
  "status": "deliverable",
  "risk_score": 96,
  "is_catch_all": false,
  "is_role": false,
  "is_disposable": false,
  "mx_records": ["aspmx.l.google.com"],
  "smtp_check": "passed",
  "syntax_valid": true,
  "credits_used": 1
}

// Returned in under 500ms, ready to route into Instantly

Pricing

Pricing that fits how Instantly operators actually buy verification

A recurring credit pool for steady weekly list uploads. A lifetime pool for agencies running multi-client campaigns at scale.

Monthly

For solo operators and small teams running daily Instantly list uploads.

$9.99 /month

check300,000 credits per cycle
checkVerifies roughly 10,000 leads per day
checkFull Finder, Verifier, Enrichment APIs
check25,000 exports per month
check600 req/min rate limit
checkPriority email support

Start Free Trial

Annual

Lock in 20% savings on a year of pre-flight verification credits.

$7.99 /month

Billed $95.88 per year

check300,000 credits per cycle
checkFull Finder, Verifier, Enrichment APIs
check25,000 exports per month
check600 req/min rate limit
checkUnlimited Signals
checkPriority email support

Choose Annual

Lifetime

For agencies verifying lists across multi-client Instantly workspaces.

$249 one-time

check2,000,000 credits (lifetime pool)
checkFinder and Verifier APIs
check5,000 exports per month
check1,000 Enrichment calls per month
check25 Signals per month
check300 req/min, lifetime access

Get Lifetime

Top-up credit packs for overflow Instantly campaigns

Stack on any plan. Credits never expire. Useful when a new client signs and a 500K Apollo export needs scrubbing before launch.

10K

credits

22K

credits

42K

credits

$14.99

100K

credits

$29

250K

credits

$59

Use cases

Four places Mailsfinder protects Instantly sends

From first-time list scrub to mid-sequence re-verification, the same credit pool powers all four playbooks.

cleaning_services

Pre-campaign list scrub

Every Apollo, Sales Navigator, or scraper export gets cleaned before it touches Instantly. Average shrinkage of 15 to 25% on the input, bounce rate under 1% on the output.

replay

Mid-sequence re-verify

For sequences that run 30+ days, re-verify leads on day 14 before the next email step fires. Catches addresses that went stale during the campaign so bounces stay flat across the full sequence.

groups

Multi-client agency cleaning

One Lifetime credit pool covers verification across every Instantly workspace your agency runs. Tag credits by client in the dashboard, bill through, and never juggle multiple verifier subscriptions.

policy

Lead vendor quality audit

Buying lists from a data vendor? Run a 5,000-row sample through Mailsfinder before paying for the full batch. If deliverability sits under 80%, push back on the invoice or renegotiate price.

FAQ

Questions Instantly operators ask before wiring in Mailsfinder

How does a high bounce rate affect my Instantly campaigns? expand_more

Instantly relays through your own connected mailboxes, so bounce damage lands on your sending domain and IPs. A bounce rate above 5% triggers spam folder placement at Google and Outlook, and sustained bounces over 10% can suspend the mailbox at the provider level. Mailsfinder pre-flight verification keeps bounces under 1% so Instantly campaigns stay in the primary inbox.

What is the recommended Apollo plus Instantly plus Mailsfinder stack? expand_more

Pull the lead list from Apollo or Sales Navigator into a CSV or via API. Push every row through Mailsfinder Verifier through Make, Zapier, n8n, or a direct REST call. Filter for status equal to deliverable, then import the cleaned file into Instantly as a new lead list. The whole sequence runs in under 10 minutes for 1,000 leads.

Can an agency run multiple Instantly workspaces against one Mailsfinder account? expand_more

Yes. Mailsfinder bills per workspace, not per Instantly seat or client. One Monthly plan at $9.99/mo gives an agency 300,000 verifications per cycle to spend across every Instantly workspace and client campaign. The Lifetime plan at $249 unlocks 2,000,000 verifications from a single shared pool, which is what most multi-client outbound agencies pick.

What are the Mailsfinder API rate limits for high-volume Instantly users? expand_more

Monthly and Annual plans get 600 requests per minute on the Verifier API. The Lifetime plan caps at 300 req/min. At 600 req/min, a 50,000-lead list completes pre-flight verification in roughly 90 minutes, fast enough to verify a list in the morning and load it into Instantly campaigns the same afternoon.

How do I rebuild sender reputation after Instantly bounces tanked it? expand_more

Pause active Instantly campaigns, run every existing lead list through Mailsfinder Verifier, and remove all rows that are not flagged deliverable. Restart sends at 30% volume for 7 days while monitoring bounce rate in Instantly analytics. Once bounces sit under 1% for a week, ramp volume back up gradually. Most domains recover inbox placement within two to three weeks of clean sending.

How does Mailsfinder compare to Bouncer or ZeroBounce for Instantly users? expand_more

Bouncer and ZeroBounce charge per email verified with no recurring credit pool, so a 10,000-list verification runs $40 to $70 each time. Mailsfinder bundles 300,000 verifications into the $9.99 Monthly plan, which works out to roughly $0.000033 per check. For Instantly users running steady weekly list uploads, the recurring subscription model is dramatically cheaper than pay-as-you-go verifiers.

Does Mailsfinder support real-time verification for live Instantly campaigns? expand_more

Yes. The Verifier API returns a deliverability decision in under 500ms per email. Many Instantly users wire this into webhook automations: when a new lead is added mid-campaign or imported from a webform, Mailsfinder verifies in real time and only deliverable rows are pushed into the active Instantly sequence.

Can I top up credits if a large Instantly campaign exceeds my monthly pool? expand_more

Yes. Credit packs stack on any plan and never expire: 10,000 credits for $5, 22,000 for $9, 42,000 for $14.99, 100,000 for $29, and 250,000 for $59. Useful when a new client signs and you need to verify a 500K-lead Apollo export before loading into Instantly.

Stop letting bad lists cook your Instantly mailboxes

Start with 50 free credits. No card needed. Wire Mailsfinder into your Make or Zapier scenario in under 10 minutes and every list that touches Instantly is pre-flight verified from day one.

Start Free Trial arrow_forward Talk to Sales calendar_month