---
title: "Contact Verification: Real Multi-Port SMTP Checks"
description: "Verify syntax, MX records and mailbox existence with real SMTP handshakes across ports 25, 465, 587 and 2525. 99.8% accuracy, single results in under 2 seconds."
canonical: "https://emailshield.co/features/contact"
last-updated: "2026-08-22"
---

> Verify syntax, MX records and mailbox existence with real SMTP handshakes across ports 25, 465, 587 and 2525. 99.8% accuracy, single results in under 2 seconds.

EMAILSHIELD

Platform Features

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Blacklist Monitoring

Contact Verification

DMARC Monitoring

Email TesterSoon

Inbox Placement TestsSoon

Spam CheckerSoon

Contact Verification

Feature Overview

# Contact Verification

Advanced multi-step verification process that checks syntax, MX records, and performs real-time SMTP handshakes without sending emails.

### Sender reputation

Avoid high bounce rates by sending only to valid addresses.

### Inbox placement

Clean lists help you avoid spam traps and improve rates.

### Better delivery

Reduce chances of sending to invalid addresses.

Real-time Validation

### Contact Verification

#### Syntax errors.Check for syntax errors in email addresses.

#### Domain validity.Verify domain is valid and active.

#### Mailbox existence.Check if mailbox can receive emails.

Contact Verification