Validate Your Email List Before Sending
Validate Your Email List Before Sending with Cleanlist's waterfall enrichment. Upload a CSV or connect your CRM — 30 free credits to start.
Start Free — 30 CreditsThe Problem
Sending to an unvalidated list is the email marketing equivalent of driving without insurance — everything is fine until it is catastrophically not. ISPs now use engagement signals (opens, clicks, complaints) alongside bounce rates to determine inbox placement. A single campaign sent to a stale list can tank your sender score from 95 to below 70, and recovery takes 30-60 days of carefully managed sending volume.
How Cleanlist Solves This
Cleanlist's list validation checks every address against five validation layers before you press send: syntax and formatting, DNS and MX records, SMTP mailbox existence, catch-all domain detection, and behavioral activity scoring. The output is a validated list segmented by deliverability risk, so you can send confidently to safe addresses and suppress risky ones.
Sender Reputation Recovery Takes 42 Days — Prevention Takes 3 Minutes
Return Path's 2025 Sender Score Benchmark analyzed 3,200 sending domains and found that domains experiencing a bounce rate above 5% on a single campaign took an average of 42 days to return to their pre-incident sender score. During recovery, inbox placement dropped by 18-35%, meaning a significant portion of legitimate emails were silently routed to spam. The recovery process requires progressively increasing send volume to only the most engaged subscribers — essentially re-earning trust from ISPs one small batch at a time. By contrast, validating a 25,000-address list with Cleanlist takes under 5 minutes and costs approximately $125. For context, the revenue impact of 42 days of reduced deliverability for a company sending 50,000 emails per week is estimated at $6,300-15,000 in unrealized email-driven revenue. The ROI case for pre-send validation is 50-120x within a single campaign cycle.
Source: Return Path (now Validity) Sender Score Benchmark 2025
How It Works
Upload Your Pre-Send List
Upload the exact list you plan to send to — CSV, Excel, or direct paste. Cleanlist validates the list as-is, including any segmentation columns you have, so you can re-import the validated version without losing your audience structure.
Syntax & Formatting Pass
Addresses with missing @ signs, double dots, invalid TLDs, or non-ASCII characters are flagged immediately. Common typos (gmial.com, yaho.com, outlok.com) are auto-corrected where unambiguous, saving recoverable addresses.
Domain Health Check
Each domain is checked for active MX records, SPF/DKIM/DMARC configuration, and blacklist status. Domains that cannot receive mail — or that are on major blocklists — are flagged so you can remove those addresses before they generate hard bounces.
Mailbox-Level Validation
For domains with active mail servers, each individual mailbox is validated via SMTP protocol simulation. This confirms the specific address exists and can accept mail — not just that the domain is valid.
Deliverability Segmentation
Your list is segmented into four tiers: Safe (verified mailbox, active domain), Acceptable (valid but on catch-all domain), Risky (intermittent server, greylisted), and Suppress (invalid, trap, or blocklisted domain). Send only to Safe + Acceptable for optimal deliverability.
Key Benefits
98% Email Accuracy
Real-time email verification catches bounces, catch-alls, and disposable addresses before they cost you.
15+ Data Providers
Waterfall enrichment across multiple providers means higher match rates than any single-source tool.
No Code Required
Upload a CSV, connect your CRM, or use the API. Works however your team prefers.
30 Free Credits
Start enriching immediately. No credit card, no sales call, no commitment.
Manual Process vs Cleanlist
| Feature | Manual | Cleanlist |
|---|---|---|
| Validation layers | 1 layer (send and see what bounces) | 5 layers (syntax, DNS, MX, SMTP, behavioral) |
| Typo auto-correction | Not available — typos become hard bounces | Common domain typos auto-corrected (saving 2-4% of list) |
| Blocklist checking | Manual lookup on MXToolbox (one domain at a time) | Bulk check against 50+ blocklists in real-time |
| Time to validate 25K addresses | Not feasible manually — relying on post-send bounce data | 3-5 minutes (automated pipeline) |
| Sender score protection | Reactive — damage happens before detection | Preventive — risky addresses removed before sending |
Frequently Asked Questions
How accurate is Cleanlist's data?
+
Cleanlist achieves 98% email accuracy through real-time verification and cross-referencing across 15+ data providers. Every record is validated before delivery.
How many free credits do I get?
+
Every new account starts with 30 free credits. Each credit processes one record (enrichment, verification, or lookup). No credit card required to start.
What data providers does Cleanlist use?
+
Cleanlist uses waterfall enrichment across 15+ providers including major B2B data sources. The system automatically selects the best provider for each record to maximize match rates.
Can I connect my CRM?
+
Yes. Cleanlist integrates with HubSpot, Salesforce, and other CRMs. Enriched data syncs back automatically. You can also upload CSV files or use the REST API.
How long does it take to validate my data?
+
Most jobs complete in under 2 minutes for up to 10,000 records. Larger files are processed in batches with progress updates.
What is the difference between email validation and email verification?
+
In practice, the terms are used interchangeably. Technically, 'validation' emphasizes checking that an email conforms to standards and rules (syntax, domain validity, list hygiene), while 'verification' emphasizes confirming that a specific mailbox exists and can receive mail. Cleanlist's validation service includes both — syntax checks and SMTP verification — so the distinction does not matter in terms of what you get.
Should I validate my list every time I send a campaign?
+
If you send to the same list weekly, validating monthly is usually sufficient. If your list includes recently acquired contacts (from events, purchased lists, or webforms without double opt-in), validate before every campaign. The cost of validation ($0.005/email) is negligible compared to the cost of a sender reputation hit from a single bad campaign.
Can Cleanlist validate emails in languages other than English?
+
Yes. Cleanlist validates email addresses on any domain regardless of language. The validation is protocol-based (DNS and SMTP), not language-dependent. International domain names (IDN) with non-Latin characters are fully supported.
Ready to validate your email list?
Start with 30 free credits. No credit card required. See results in under 2 minutes.
No credit card required