How do I clean an email list for free?

Paste the list or upload a CSV into the free validator. It de-duplicates, checks syntax, TLD, DNS/MX, SPF/DMARC, disposable domains and role accounts, then lets you export only the addresses that passed.

How often should I clean my email list?

Monthly if you send weekly, and always before importing into a new platform or emailing a list that has been dormant for more than 90 days. B2B lists decay roughly 2% per month.

Should I delete role accounts like info@?

For cold outreach, usually yes — they go to shared inboxes and generate more complaints. For support or transactional mail they are legitimate, so segment rather than delete blindly.

Does cleaning a list improve deliverability?

Yes. Lower hard-bounce and complaint rates are two of the strongest signals inbox providers use, so a clean list directly improves inbox placement for the rest of your subscribers.

How to clean an email list

Updated September 3, 2026

A dirty list is the fastest way to damage sender reputation. Cleaning is a repeatable checklist, not a one-off task — run it before every significant send, and always before importing into a new sending platform.

1. De-duplicate and normalise

Duplicates inflate your count and can trigger multiple sends to the same person. Trim whitespace, lowercase the domain and collapse duplicates before anything else. The validator does this automatically on paste or CSV import.

2. Remove structurally impossible addresses

Drop anything that fails RFC syntax, uses a non-existent TLD (.con, .gmial.com), resolves to nothing, has no MX record, publishes a null MX, or points at a parked domain. These can never deliver, so removing them is free risk reduction.

3. Deal with disposables, role accounts and typos

Disposable and burner domains never engage. Role accounts (info@, sales@, admin@) go to shared inboxes and complain more. Typo domains often belong to someone else entirely. Flag all three and decide per segment whether to drop or repair them.

4. Segment by mailbox provider

Knowing which addresses sit on Google Workspace, Microsoft 365, Yahoo or a business domain lets you warm up and throttle sends per provider — Microsoft in particular punishes bursts to low-quality lists.

5. Verify the survivors, then re-engage carefully

Run SMTP verification on the addresses that passed the free layers, and split the result: send to confirmed mailboxes first, hold unknown and catch-all addresses for a smaller, well-warmed campaign.

How often should you clean?

Around 2% of a typical B2B list decays every month as people change jobs. Clean monthly if you send weekly, and always clean any list that has been sitting unused for more than 90 days.

Try it on your own list

Run the free validator on any address or CSV, then spend credits only on the addresses that survive.

Free email validator Verification credits

Frequently asked questions

Keep reading

How to verify an email address
Step-by-step guide to verifying an email address for free: syntax, domain, MX records, disposable checks and SMTP verification, plus how to check a whole list.
Email validation vs email verification
Validation checks whether an address could receive mail; verification confirms the mailbox exists. Learn what each one catches, what it costs and when to use both.
Why do emails bounce?
The real causes of hard and soft email bounces, what each bounce code means for your sender reputation, and how to cut your bounce rate before the next send.