Agencies
Email List Cleaning & Validation for Agencies
Verify client email lists before every campaign. Improve deliverability, boost open rates, and prove ROI with clean data.
End-to-End Protection
Your complete email quality pipeline
From signup to send, Mailchk protects every stage of your email lifecycle. Block bad addresses, clean your lists, score deliverability, and verify inbox placement.
Block at the Gate
Real-time signup protection
Stop fake, disposable, and scam emails the moment a user hits your signup form. Our API responds in under 50ms — before the page even finishes loading.
Clean Your Lists
Bulk CSV validation & catch-all testing
Already have an email list? Upload it and we'll scrub out the fakes, catch-all addresses, and dead mailboxes. Validate thousands of emails in minutes, not hours.
Score Every Email
Risk & deliverability scoring
Get a 0-100 deliverability score and risk level for every address. Prioritize your safest contacts and flag the risky ones before they damage your sender reputation.
Test Inbox Placement
Know where your emails land
Send a test email and see exactly where it ends up — Primary inbox, Promotions, Spam, or blocked entirely. Test across Gmail, Outlook, and Yahoo before you hit send on your campaign.
Test & Capture
Inspect every email your app sends
Create disposable test inboxes and send your transactional or marketing emails to them. Inspect the full content — HTML rendering, headers, attachments, and plain text — before going live.
Protect your platform at every stage of the email lifecycle
Minutes
Clean Lists Fast
470K+
Scam Domains Tracked
15+
Validation Checks
<50ms
Per Email
Live Preview
See Client List Cleaning in Action
Watch how we process a client list — upload, validate, and get clean results in minutes.
Drop your CSV file here
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The Problem
Why Stale Email Lists Undermine Agency Campaigns
When client email lists are full of invalid addresses, every metric suffers — and so does client trust.
Stale Client Lists
Clients hand over email lists that haven't been cleaned in years — full of bounces, traps, and dead addresses.
Skewed Campaign Metrics
Invalid emails drag down open rates and click-through rates, making it impossible to demonstrate real campaign performance.
Wasted Ad Spend
Lookalike audiences built from dirty lists target the wrong people, burning through ad budgets with poor ROI.
Hard to Prove ROI
When deliverability is low, campaign results look worse than they are — making it difficult to retain clients.
Capabilities
Everything You Need to Clean Client Lists
A complete toolkit for agency email hygiene — from bulk cleaning to inbox placement testing.
Bulk List Cleaning
Upload client CSV files and clean entire lists in minutes. Get detailed reports with export options for valid, invalid, and risky emails.
Email Watchdog
Subscribe a watchdog address to client mailing lists. Every campaign is screenshotted, diffed, and checked for broken links and dead images — automatically.
Inbox Placement Testing
Test where campaign emails land across Gmail, Outlook, and Yahoo — Primary, Promotions, or Spam.
Disposable Email Detection
Remove 470,000+ known disposable and temporary email domains from client lists before campaigns.
Per-Email Risk Scoring
Every email gets a 0-100 risk score. Give clients clear data on list quality with low/medium/high/critical breakdowns.
Domain Typo Recovery
Detect typos like gmial.com or yaho.com and suggest corrections — recovering real subscribers instead of removing them.
Catch-All Detection
Identify catch-all domains that accept any email — these addresses are harder to verify and carry deliverability risk.
Recommended Products
Email Validation Tools for Agencies
Email List Validation
Clean client lists before every campaign. Upload CSVs and get detailed validation reports.
Explore List Validation NewEmail Watchdog
Monitor client campaigns automatically. Broken links, dead images, and layout regressions are caught before recipients see them.
Explore WatchdogInbox Placement Testing
Show clients exactly where their campaign emails land before sending.
Learn MoreEmail Validation API
Integrate validation into client platforms and CRMs for ongoing list hygiene.
Explore APIPlugins & SDKs
Drop validation into client WordPress sites, landing pages, and forms.
View PluginsDon't just take our word for it
See why teams rely on Mailchk to keep their email lists clean
"Mailchk reduced our fake signups by 89%. The API is incredibly fast and the documentation is excellent."
Noel S
CTO, MyBrands Group
"We integrated Mailchk in under an hour. It catches disposable emails that other services miss."
Stephen M
Lead Developer, TRTCompare
"Finally, a solution that actually works. Our email deliverability improved by 40% after implementing Mailchk."
Michael G
Product Manager, Evernu
"The real-time validation is a game changer. No more wasted resources on fake accounts."
Joe S
Founder, Moojority
"Mailchk handles our 100k+ daily validations without breaking a sweat. Incredible performance."
Katie E
DevOps Lead, CVS
"Switched from a competitor and never looked back. Better accuracy, better pricing, better support."
Brendan O
Tech Lead, CardGenr
"Mailchk reduced our fake signups by 89%. The API is incredibly fast and the documentation is excellent."
Noel S
CTO, MyBrands Group
"We integrated Mailchk in under an hour. It catches disposable emails that other services miss."
Stephen M
Lead Developer, TRTCompare
"Finally, a solution that actually works. Our email deliverability improved by 40% after implementing Mailchk."
Michael G
Product Manager, Evernu
"The real-time validation is a game changer. No more wasted resources on fake accounts."
Joe S
Founder, Moojority
"Mailchk handles our 100k+ daily validations without breaking a sweat. Incredible performance."
Katie E
DevOps Lead, CVS
"Switched from a competitor and never looked back. Better accuracy, better pricing, better support."
Brendan O
Tech Lead, CardGenr
Clean Client Lists and Boost Campaign ROI
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