Email List Cleaning — Improve Deliverability Before You Send
A clean list is the single biggest factor in email deliverability. Remove invalid addresses before they bounce, and protect the domain reputation you've spent years building.
- What is email list cleaning?
- Email list cleaning is removing the addresses on a list that would bounce, harm your sender reputation or never convert. Mailbeam verifies every address on the list and marks each one deliverable, undeliverable or risky, with a reason: a hard bounce, a disposable domain, a role address like info@, or a catch-all domain that accepts everything and confirms nothing.
What Mailbeam checks
Every verification runs 7 checks in parallel and returns a structured result in under 100ms.
Batch processing up to 500k
Submit your entire list via API or as a CSV in the dashboard. Processing is asynchronous — no connection timeouts or dropped jobs.
Three-way segmentation
Every address is classified as Deliverable, Risky, or Undeliverable. Make a different decision for each segment.
Bounce rate protection
Removing undeliverable addresses before sending keeps your bounce rate below the 2% ISP threshold that triggers reputation damage.
Sender reputation safe
Disposable and role-based emails have near-zero engagement and high spam complaint rates. Removing them before sending improves your reputation score.
Compatible with any ESP
Export clean results and import into Mailchimp, SendGrid, Klaviyo, Lemlist, Apollo, or any other sending platform.
Scheduled re-verification
Set up regular re-verification jobs via the API to keep your list fresh as email addresses change.
How it works
Export your current list
Pull your contact list from your CRM, ESP, or database as a JSON array or CSV.
Submit to the batch API
POST the email array to Mailbeam's batch endpoint. Include a webhook URL to be notified when complete.
Review segmented results
Results arrive classified as Deliverable, Risky, or Undeliverable — each with a score and individual check breakdown.
Import the clean segment
Import the Deliverable segment back into your ESP. Suppress the Undeliverable segment. Decide on Risky based on your tolerance.
When to use it
Before every major campaign
Run a cleaning pass before any campaign to a list older than 90 days. Even a quarterly send can have 10%+ decay.
After importing contacts
Any contact imported from trade shows, events, bought lists, or third-party sources should be verified before entering your system.
When bounce rate exceeds 1.5%
If your bounce rate is climbing, a cleaning pass can often identify the problem segment and bring it back under control.
Quarterly maintenance
Business email churn runs at 30% per year. A quarterly cleaning pass keeps your database accurate and deliverable.
Frequently asked questions
How much does email list cleaning cost?
Mailbeam charges per verification. The cost of cleaning a list of 10,000 addresses is typically under €5 on the Starter or Growth plan. Calculate your cost on the pricing page.
How do I know what percentage of my list is invalid?
Submit a sample of 500-1,000 addresses from your list using the free tier or Starter plan. The percentage of Undeliverable results gives you a good estimate of overall list health.
Should I delete undeliverable contacts?
At minimum, suppress them from all campaigns. Whether to delete depends on your retention policy. Under GDPR, you should not store inaccurate personal data without purpose.
Can I clean a list from Gmail or Excel?
Export the email column as a text/CSV file, parse it in your code, and submit the array to the batch endpoint. The API accepts a simple JSON array of email strings.
Ready to integrate?
Free tier includes 1,000 verifications/month. No credit card required.