Verification Process Overview

The Inbox Email Verification Tool performs a multi-layered validation process designed to ensure email addresses are real, secure, and safe to send to. Each layer checks a specific part of the email lifecycle — from syntax to domain configuration — producing a detailed deliverability and trustworthiness score.

Syntax Check

Confirms the email is properly formatted (e.g., user@domain.com) and follows international email syntax standards (RFC 5322). Invalid formats are filtered out immediately to prevent wasted lookups.

MX Record Lookup

Detects whether the domain has valid Mail Exchange (MX) records — proof that it can receive emails. If no MX servers are found, the address is marked as undeliverable.

SMTP Handshake

Simulates a live connection to the recipient’s mail server using SMTP. This step confirms whether the mailbox exists without actually sending a message.

Catch-All Detection

Identifies domains configured to accept mail for any address, even if the specific mailbox doesn’t exist. These are flagged as “catch-all” so you can decide whether to include them in your campaigns.

Spam Trap Screening

Scans against a database of known trap domains and honey-pot addresses that blacklist senders. This protects your sender reputation and keeps your IP out of spam monitoring systems.

HTTPS/TLS Health (cURL)

Uses curl to probe the domain’s website over HTTPS: verifies TLS/SSL status (certificate validity, expiry, hostname match), follows redirects, and surfaces handshake/verification errors. The result appears in the cURL column and contributes to the Risk Score.

Website Content Signals

Heuristics like content-to-tag ratio and common “Access Denied / 403” patterns help spot blocked, empty, or suspicious sites (useful when mail looks fine but the domain is sketchy).

SPF & DKIM Validation

Checks whether the domain implements SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) records — essential authentication measures that confirm messages truly originate from authorized sources.

Final Status Report

Based on all previous checks, the system categorizes each email as: Valid, Invalid, Risky, or Spam Trap. This helps you clean your contact lists, improve deliverability rates, and maintain compliance.