---
title: How Verify 550 Works
description: "Verify 550 uses a prominent mail transfer protocol called SMTP (Simple Mail Transfer Protocol) to check if the user’s email address is invalid or non-working without sending actual emails to that recipient address. Although this is a simple approach, there…"
url: "https://verify550.com/documentation/how-verify-550-works-2/"
updated: "2025-10-11"
category: Email Verification
---

# How Verify 550 Works

Verify 550 uses a prominent mail transfer protocol called SMTP (Simple Mail Transfer Protocol) to check if the user’s email address is invalid or non-working without sending actual emails to that recipient address.

Although this is a simple approach, there is an overhead involved with SMTP, and email servers often behave unexpectedly.

Therefore, many companies rely on Verify 550 to provide email verification. We have been in the email and security industry for the last 10 years and have gained a reputation in the email verification process.

Here are our steps we use for emails validation and verification:

**Email deduplication** – Domains that match our existing database of invalid emails are removed

**Domain validation** – DNS entries for every email address are checked and validated

**Spam-trap removal** – Spam-traps and disposable emails are detected

**Spamcop removal** – Matches and removes against updated static list of 9 million spamcop traps

**Risk validation** – Remove all of the domains that match our existing database of invalid emails

**Syntax verification** – Email address syntax is verified according to IETF standard

**MTA validation** – Checks if a Mail-Transfer-Agent has a valid MX Record

**Protestor removal** – Matches against updated static list of 300 million protestors and growing

**Litigator removal** – Matches against updated static list of 12,000 litigators worldwide

**Botclickers removal** – Matches against updated domain, email and IP’s of known botclickers

**Department role removal** – Matches against emails that are shared with groups or departments

**Domain blacklist** – Matches and removes against known blacklist domains

**Disposable removal** – Matches and removes against temporary and/or disposable emails