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Aastha Shaw / June 1, 2019 March 14, 2025

Email Validation: What Is It and Why Do You Need It?


What Is It and Why Do You Need It

You spend hours crafting engaging content, designing attractive layouts, and segmenting your audience. But what if all your efforts go to waste because your emails never reach their intended recipients?

One in ten emails either get lost in the spam folder or blocked by the email service provider. This can hurt your email campaign performance, reputation, and revenue.


One of the main reasons for this low deliverability rate is the poor data quality and invalidity of your email list. If your email list contains invalid, outdated, or fake email addresses, you are likely to face high bounce rates, spam complaints, and low engagement. 😞

That's why email validation is essential for maintaining good data quality of your lists and good campaign performance. If you are thinking about what email validation means, how it can help you, and what’s the proper way to validate email addresses, then you are at the right place.

Now to answer the most important question…

Table of Content


● What Exactly Is Email Validation?
● Email Validation V/s Email Verification — Are They Same?
● How Email Validation & Verification Benefits Your Email Campaigns?
Removes emails that degrade your email list quality
Minimizing bounce rates
Saves your sender’s reputation
Solves low deliverability issues
Reduces the chances of being blacklisted
Saves resources being spent on chasing invalid leads
Increases email campaign’s ROI
● The Various Ways To Validate Email Addresses
Regex for email validation
Real-time email validation
Post email validation or double opt-in
Bulk email validation
● What is An Email Validator?
What should you look for in an email validation tool?
● Clearout — The Best Email Validation Tool
● What Comes After Email Validation?
● Frequently Asked Questions (FAQs)

What Exactly Is Email Validation?


Email validation is the process of verifying the validity and deliverability of an email address. It helps you remove invalid, inactive, risky, or bad email addresses from your list and keep only the ones that are real and engaged.

It also saves you from typos while submitting the forms and leads to incorrect data submission, keeping you from reaching out to your primary targets.

The email validation process helps you increase your email campaigns’ effectiveness, email deliverability, and customer satisfaction. But, before we dive into how exactly email validation improves your email campaigns, let’s get this out of the way…

Email Validation V/s Email Verification — Are They Same?


Even though both terms are used interchangeably and ensure the accuracy and quality of your email lists, email validation and email verification are two different processes.

Email validation involves checking email syntax, email address format, and structure of an email address to ensure it is correctly entered and follows the standard rules. The primary goal is to identify typos, misspellings, or formatting errors that can make an email address “invalid”.

On the other hand, email verification goes beyond syntax and format checks. It involves a more in-depth verification process to determine the deliverability of an email address. It includes checking the DNS records, performing an SMTP handshake, and simulating sending an email without actually delivering it. The purpose is to validate the existence of the email address beyond its format and ensure it can receive messages.

Email ValidationEmail Verification
Checks for the email address format and syntax.Checks if the email address exists.
Helps maintain a clean email list free of typos.Helps build a high-quality email list with real leads and enhances deliverability.
Offers low-level accuracy on whether an email address is real/active.Offers high-level accuracy on whether an email address is real/active.
Involves simple methods such as spelling, regex, syntax, and format check.Involves complex methods such as DNS lookup, SMTP verification, and mailbox simulation.

Both methods when implemented properly lead to better data quality and campaign performance. Here’s how…

How Email Validation & Verification Benefits Your Email Campaigns?


● Removes emails that degrade your email list quality


The most obvious and risky consequence that email validation and verification saves you from is stopping invalid & bad email addresses (disposables, spam traps, blacklisted, catch-alls, etc) from entering and degrading the quality of your email lists.

Even a 1% increase in bad email addresses in your list can drop your email deliverability by 10%. With proper email validation and verification, you ensure that your sales teams and email campaigns are running on accurate data leading to further benefits.

● Minimizing bounce rates


The email validation and verification results let you know which email addresses are incorrect, undeliverable, role-based, accept-all, and so on. With this knowledge in hand, you can decide to remove addresses that offer no guarantee of a secure delivery and might result in a bounce. Hence, the process keeps your email lists clean and minimizes the chance of email bounces by 90%.

● Saves your sender’s reputation


When you send out emails, you create a reputation among ISPs and ESPs. This reputation is commonly known as sender reputation and is built on factors such as, how often your emails are flagged as spam or what proportion of your outgoing email bounces back.

Using a verified email list ensures you don’t look like spam or you don’t send out emails to any address that will reject your email, causing bounces. This in return helps you maintain a good sender’s reputation with your ESPs and ISPs.

● Solves low deliverability issues

If you have low deliverability and you don’t take measures to fix it, ISPs think of you as a spammer. This leads to more and more of your emails landing in the spam folder, even for your engaged recipients.

The best way to solve the deliverability issue is to validate email lists thoroughly. With proper validation and verification methods, you reduce bounces and improve the sender’s reputation, gaining your ISP’s trust and achieving better deliverability.

● Reduces the chances of being blacklisted


Your domain or IP address may get blacklisted if you have very low engagement, and your email list contains outdated/invalid email addresses or spam traps. All of your subsequent emails are going to be delivered to spam, which is not where you want them to be.

For instance, the likelihood that your account would be blacklisted increases the more hard bounces you receive or in case you land into a spam trap. You lower these risks by authenticating and verifying the email addresses on your list.

● Saves resources being spent on chasing invalid leads


Most ESPs offer plans with prices that depend on how many members you have on your list. You may find yourself paying a larger subscription fee without cause if it turns out that your list is bloated with hundreds of invalid email addresses.

Maintaining a valid and clean email list and avoiding subscription fees are both made possible by running an email validation.

● Increases email campaign’s ROI


You send out fewer emails when you have a cleaned, verified email list. Moreover, the emails you send out are precisely targeted. Better email targeting increases the chance of engaging the receiver. Your emails are more pertinent in their eye and they are more inclined to make a purchase.

So, with email validation, your resources are being used more effectively, your expenses decrease, and your revenues most likely increase. This increases your ROI, for every dollar you invest.

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The Various Ways To Validate Email Addresses


1. Regex for email validation


A regular expression, or regex, is a string of characters that describes a search pattern. Regex email validation can be used to validate email address format.

However, there are a few drawbacks to using Regex for email validation.

First, it is extremely limited, as it does not permit the use of unusual email addresses. Even though characters like ! #$ % &'*+-/=? '| can be used in an email address, but when used before the @ symbol, the regex method would show the email address as invalid.

Second, Regex for email validation can only validate emails for a specific pattern. It fails to check other important factors, such as whether the email domain and user account exist, putting it at a disadvantage when compared to other validation methods.

2. Real-time email validation


Real-time email validation is a more advanced and accurate way to check if an email address is deliverable. It allows you to validate email addresses as they are entered into the signup form by performing a series of checks, such as DNS lookup, SMTP handshake, mailbox existence, catch-all verification, etc.

You can use tools like Clearout email validation & verification to validate your leads' email addresses in real time.


You can easily use Clearout's REST API, JS Widget, or WordPress Plugin to integrate it with your landing pages, forms, etc. Clearout real-time email validation also helps you filter out unwanted emails, spammy domains, disposable accounts, and more.

3. Post email validation or double opt-in


Post-email validation, also known as double opt-in, is another effective method for determining whether an email is valid and whether the domain exists. In this method, a confirmation email is sent to the provided email address, and the user then confirms their email address to sign up.


However, if an email address is entered incorrectly, the user will not receive a confirmation email. And if they miss the typo and try again with the correct email address, you'll lose that lead and their email address.

Hence, it is best to employ both a real-time validation tool and the double-opt-in method to detect any typos or invalid email addresses at the time of entry. This will assist you in capturing high-quality leads, resulting in increased deliverability and conversion rates.

4. Bulk email validation


Bulk email validation is used to clean and validate emails that have already entered your database.

If you've never validated email data before, using a bulk email validator is a good way to get rid of unwanted email addresses, which leads to lower bounce rates and a poor sender reputation.


However, if the majority of the email addresses in your database are invalid, you will not have a large enough email list to send out your email campaigns.

Therefore, it is preferable, to begin with, a real-time email validation solution to check email address validity and build a quality list, avoid extra costs, client annoyance, and the risk of a negative sender reputation.

What is An Email Validator?

An email validator or an email validation tool checks if an email address is valid and deliverable by verifying the syntax, domain, and mailbox of an email address. An email validator also provides additional information about the email address, such as the email account type, safe-to-send score for better deliverability, etc.

What should you look for in an email validation tool?

Here is a basic feature checklist that a good email validation tool should have:


You should also consider whether the tool provides the type of verification you require and whether it integrates with the tools and apps you already use.

Clearout — The Best Email Validation Tool

Clearout Email Validation is one of the best tools on the market, with a 99% accuracy rate. While it checks all of the above boxes, it also has some unique features, such as autosuggestion and allowlist/blocklist email domains, that help you identify and prevent fraudulent signups.

It provides several methods for validating email addresses, including quick validation, bulk validation, and real-time validation via REST API, Javascript widgets, and WordPress plugins.

Furthermore, Clearout integrates with hundreds of sales and marketing tools, allowing you to easily use Clearout with your ESP, CRM, and other favorite tools. You can even validate your data on Google Sheets using the Clearout add-on. That's incredible, isn't it?


👉 Read this unbiased comparison blog from Lemlist wherein Clearout is rated 5 stars.

What Comes After Email Validation?


It is very common for a user to create an email account only to never use it. Alternatively, the leads on your email list may change jobs and delete an old email address that was once valid. They may even unsubscribe from your emails or block you.

If you do not clean your email lists regularly and continue to send emails to these addresses, it will lead to a negative sender reputation and a bad deliverability score.

Hence, to improve your email campaign results, you should verify emails before each email campaign or at regular intervals, and not only when they are added to your email list. This will eventually lead to the growth and expansion of your brand, as well as an increase in ROI.

Get Clearout for real-time validation and maintain a clean, valid, high-quality email list.

Try Clearout Now

Frequently Asked Questions (FAQs)


Who uses email validation?
Email Marketers and Cold Email Experts use email validation to make sure their emails land in the intended recipients inbox.
How do you verify and validate email addresses?
Email address verification and validation involve confirming the authenticity and deliverability of an email address. This can be done through manual checks, automated tools, or third-party services. Steps include checking syntax, domain existence, mailbox existence, and whether the address bounces.
How does email validation work?
Email validation typically involves several checks to ensure an email address is valid and deliverable. This includes examining the format, validating the domain through DNS records, and using SMTP protocols to simulate sending an email and checking for successful delivery or bounces. Some services also check against known disposable or temporary email domains.
How accurate are email validation services?
The accuracy of email validation services can vary based on the provider you choose. High-quality email validation services like Clearout utilize advanced algorithms and databases to cross-reference email addresses against various sources, including domain records, SMTP verification, and other data points. This approach enhances accuracy by identifying invalid, temporary, or disposable email addresses, as well as detecting potential spam traps and known bounces.

However, it's important to note that no email validation service can guarantee 100% accuracy due to the constantly changing nature of email addresses and the evolving tactics used by spammers.

Clearout guarantees a 98%+ accuracy as their system validates and refines an email address through 20+ validation checks.
What is the best email validator?
One of the reputable email validation services is Clearout. It provides email validation and verification services that include syntax checks, domain verification, and mailbox existence checks. It also marks the guaranteed deliverables on your email list, which helps you minimize your email bounce rate to 0-3%.
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