About

In email marketing, data hygiene is not a luxury; it is the foundation of infrastructure reputation. Sending campaigns to invalid, disposable, or nonexistent addresses triggers spam filters, drastically reducing Deliverability Rates. This tool is engineered for developers and marketers who require granular analysis of their contact lists without uploading sensitive data to third-party servers.

Unlike basic regex parsers, this system executes a multi-stage audit. It evaluates syntax against RFC 5322 standards, queries the Domain Name System (DNS) for MX records via secure DNS-over-HTTPS protocols, and cross-references an internal database of over 2,500 disposable and high-risk domain patterns. Furthermore, it identifies Role-Based addresses (e.g., admin, support) which are notorious for lowering engagement metrics.

Formulas

The core validity score S is calculated using a weighted vector model based on four boolean checks: Syntax (syn), MX Record (mx), Disposable Status (disp), and Role Status (role).

S = {

INVALID if ¬syn ∨ ¬mxRISKY if disp ∨ roleCLEAN otherwise

To detect typos, we apply the Damerau-Levenshtein distance, which accounts for transpositions of adjacent characters (common in typing). The similarity index J is compared against a threshold τ:

J(a, b) ≤ τ &implies; Suggestion Generated

Reference Data

Classification	Risk Level	Definition	Impact on Sender Score
Valid	LOW	Syntax correct, Domain exists, MX records found.	+ Positive (Safe to send)
Disposable	CRITICAL	Temporary inbox (Burner email). Lasts 10min to 24h.	− High Bounce Risk
Role-Based	HIGH	Generic prefix (admin, info). Non-personal.	− Low Open Rate / Spam Complaints
Invalid Syntax	CRITICAL	Does not conform to email formatting standards.	− Hard Bounce (Immediate)
MX Missing	CRITICAL	Domain has no mail server configured.	− Hard Bounce
Typos	MEDIUM	Misspelled domains (e.g., gamil.com).	− Lost Opportunity

Frequently Asked Questions

Yes, your data is 100% safe. This tool operates entirely Client-Side. Your email list is processed within your browser's memory using JavaScript. The only data leaving your device are anonymous DNS requests to Google's Public DNS to verify if a domain exists. We do not store, save, or transmit your CSV files.

Role-based emails (like info@, support@, admin@) are managed by teams or automated systems, not individuals. They typically have very low engagement rates. More importantly, if one person in the group marks your email as spam, the entire domain might block you. High-quality lists exclude these addresses.

Our algorithm identifies common domain typos (e.g., [email protected] -> [email protected]) using Levenshtein distance. The "Bulk Fix" button automatically applies these corrections to your list, saving you hours of manual editing and recovering potential lost leads.

Some mail servers (like Yahoo or corporate firewalls) employ Greylisting, where they temporarily reject a first request to see if the sender retries. Since this is a static check tool, we may flag these as "Unknown" or "Valid" based on the domain's MX records, but we cannot confirm the specific mailbox without sending a real email.

While the tool is optimized, browser memory is limited. We recommend processing lists in batches of 5,000 to 10,000 emails for the best performance and to avoid browser freezing during heavy DNS lookups.