What Is Email Validation and Why Is It Important?

What Is Email Validation?
Vitalii Poddubnyi Vitalii Poddubnyi 12 august 2022, 07:08 415
For beginners

Valid email addresses are the basis of any successful email marketing campaign. This makes it necessary to verify that your email list is valid and error-free and that the mailboxes actually exist.

Errors occur, and your visitors' email addresses are sometimes entered incorectly when filling up a subscription form. This could go by unnoticed when people rush past the "Enter Your Email" field. They often misspell their mailbox names or type two letters instead of one, resulting in a useless email address.

Even the best campaign strategy will fail if your target audience doesn't receive your emails. Valid email addresses are the basis of having high email delivery rates. This is where email validation comes in.

What is Email Validation?

Email validation is the process of verifying the deliverability and validity of an email address. It executes a quick procedure that identifies typos, accidental errors or intentional misdirects. Email validation helps organize your email list and protects your sender score, maximizing your email program's efficiency.

When You Need to Validate Email Addresses

Email validation isn't something you do every day. Validating your mailing list is recommended if:

  • You've added new recipients.
  • It's been over a month since the last validation.
  • Your bounce rate is 2% or more.
  • You have low open rates.

How to Achieve Proper Email Validation?

Most email service providers (ESPs) offer email validation. You may also use free tools like ValidateEmailAddress and EmailValidator. First, you upload your email address list. Email validation tools will then check the email addresses to see if they are ok, risky, or invalid.

  1. Valid: this indicates that the email address is correct and free of errors.
  2. Risky: the recipient exists, but other factors indicate that this address may still bounce.
  3. Invalid: an invalid email address contains syntax, DNS, or mailbox errors.

Approaches to Email Validation

Marketers understand the importance of email validation, but sometimes they don't know how to implement it. To maximize your investment return, you should consider three email validation methods.

email validation

A proper email validation may include the following:

  • Syntax validation,
  • Check for disposable emails,
  • DNS lookup,
  • Mailbox ping,
  • Scan for apparent typos

Syntax Validation

It is the simplest method for validating and verifying emails. It validates email addresses and returns an error when any of its required parts are missing: the parts before and after the @ symbol, the part ending in .com, .org, .net or other valid top-level domain. The disadvantage of syntax verification is that it does not guarantee that this is a functional email address, only that it has all the necessary parts to appear valid.

Let's look at a regular email address: john@unione.io. It consists of local (john) and domain (unione.io) parts, divided by the @ sign.

The local part can contain:

  • alphanumeric characters – A to Z (both upper and lower case) and 0 to 9;
  • printable characters – !#$%&'*+-/=?^_`{|}~;
  • a dot.

You cannot start and end the local part with a dot, and you can't use many dots in a row like john..lennon@unione.io. The domain part can contain alphanumeric characters (upper and lower cases) and also a hyphen (-), but not as its first or last character. Mailbox names can be case sensitive, whereas domain names aren’t.

Look for Disposable Emails

A disposable email address is only valid for a short period of time. You should delete any disposable addresses provided by Nada, Mailinator, or other similar services using a third-party API like InboxHit. You can also use a regular expression to search your mailing list for domains that are used for temporary email addresses.

DNS Lookup

The process of requesting a DNS record from a DNS server is known as a DNS lookup. The MX record is of particular interest to us. A DNS entry specifies an email server for the domain’s email acceptance.

SMTP (Simple Mail Transfer Protocol) Authentication

It is possible to check if a potential recipient's domain actually has a mail server. An incomplete SMTP session without sending an email (mailbox ping) verifies that the syntax is correct and that the domain indeed has a mail server associated with it. Sure, SMTP verification isn't completely reliable; you check the existence of the mail server, but you can't always tell if a particular mailbox really exists on the server.

Look for Obvious Errors

You should also pay attention to misspellings and typos. For example, instead of somebody@yahoo.com, your email list might include somebody@yashoo.com. Such common typos can also be included in your RegEx rules.

Email Confirmation

Email confirmation, or double opt-in, is the most reliable way to ensure that an address is valid and its owner receives your email, but it also requires the most work. With this method, a web visitor can enter their email address in an online form and receive a confirmation email instantly. This process automatically verifies the email address once they confirm that they are willing to receive your emails.

email validation

However, if you already have an email list, your existing subscribers will not be pleased if you ask them to verify their identities. Sending bulk confirmation emails can also be expensive. On the other hand, if your mailing list quality is poor, you will still waste money on bounce-backs, spam reports, and a ding to your mailing reputation.

The Benefits of Email Validation

Validating your email list before sending out email campaigns has its obvious advantages.

  • It improves your email deliverability by removing invalid email addresses from your list.
  • It increases deliverability by maintaining a high Sender Score.
  • Eliminating invalid addresses saves money and increases ROI.
  • Your conversion rate will improve; more emails in inboxes means more opens and clicks and better overall performance.

How to Use Online Email Validators to Validate an Email List

Validating even a single email address would have taken much longer if we had gone through the above checklist. Luckily, you don't have to do manual validation because there are numerous ready-to-use solutions. Online email validation services offer a one-stop shop for completing each checklist step.

But, with so many email address verifiers available, how do you know which one is worth using? We checked a number of options drawing on online user feedback and chose the top ten based on the following feature list:

  • Domain check,
  • Single email verification,
  • Mail server validation,
  • Verification API,
  • Bulk email verification,
  • Syntax check,
  • GDPR compliance.

Here are our recommended online email validators:

  • ZeroBounce
  • GetEmail.io
  • HuBuCo
  • Proofy
  • Bouncer
  • EmailVerifier
  • Clearout
  • Email Checker
  • NeverBounce

An email validator must provide information about GDPR compliance because you'll be sharing your users' personal data (email addresses) with a third-party service.


The quality of your list is vital for digital marketing, but maintaining it is not an easy task. It's crucial to balance your goals, budget, and list-making precision. Whatever option you choose, you'll need an email verification service that provides a detailed analysis of your emails rather than just a pass/fail grade. It affects your marketing, sales, and email reputation.

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