Valid Email: What It Is, Who Should Check It & in What Way

Date: 2023-03-15 | Time of reading: 7 minutes (1438 words)

Checking the validity of your email contacts is a must for mass mailing, since it affects the success of sending messages and the deliverability rate. Let's make it clear what a valid email means, when it needs to be checked, who and how you should check the lists, and how to avoid adding invalid emails to the list.

What is a valid and invalid email

Email validation is the scanning of contacts for validity and reliability. Special programs called validators and verifiers are used for this process. Validation is necessary for organizations that send newsletters to a large number of addresses and use email marketing in their business. Invalid addresses include:

  1. Misspelled emails. There occur mistakes before the @ sign as well as after it in the domain part.

Misspelled email

  1. Contact duplicates.
  2. Mail traps specially designed for spam.
  3. Emails belonging to a department or a service within an organization. For example, delivery@organization.com or hr@company.us.
  4. Temporary emails created for anonymous correspondence, registration on suspicious platforms. They are created on special sites. After a certain period of time they are usually deleted.
  5. Addresses with invalid MX records.
  6. Emails that have been inactive for a long time.

In what cases validity checking is needed

If any of the following situations apply to you, you need to check your contact list and figure out the valid and invalid contacts.

1. Using a subscription form without any confirmation.

This causes a lot of invalid emails. Visitors on your site may make a misprint, use a one-time email address, or enter a random email address. To avoid this problem, pay attention to double opt-in. When a user signs up, an email is automatically sent to them asking them to confirm their email. To complete the registration, they need to click the link and prove that the email address really belongs to them and is relevant.

Example of confirming an email addressExample of confirming an email address

2. Collecting information through paper surveys

Thus, the problem is the following points: illegible handwriting of the person, inconvenient form of collecting the necessary data and errors in the given emails.

3. Using a outdated customer database

People from an old database may have already deleted or changed their email, forgotten about your organization, etc. That's why it's important to update your customer list and keep it up to date.

4. Finding more than 10% of invalid contacts

Suppose you made a mass mailing without having verified your customer base. If the service finds more than 10% of invalid contacts, you are likely to be blocked. This will obviously ruin your reputation. It is important to monitor the list of addresses for their validity from time to time.

How to check email validity

You can check your email using special online services and programs. Let's find out what exactly they check.

Mail address syntax

Addresses with spelling errors, corporate mail and duplicates are detected this way.

Domain and server

It determines if the MX record is real and correct in the customer database. If an email address is registered without this record or with an error, the email will be regarded as invalid.

Email activity

The verifier checks if the client currently uses the email address.

Top 12 services for checking the validity of email addresses

Let's look at the list of the most popular online services that check the validity of addresses, and compare them with each other. They all have common characteristics: checking email syntax, domains, and activity in the use of email. They differ in special features and tariffs.

Name of serviceFeaturesFree functionsPaid functions
BouncerEasy and user-friendly; flexible tariffs; technical support100 checkingsFrom $20 to $500 per month, custom tariff plans
DataValidationA developed API for professionals; automatic list monitoring500 checkingsDepends on the number of addresses: from $0.007 for a base of 10 000 addresses, also custom tariffs are possible
Email CheckerOnline API check; correction of mistyped addressesNo free checkings$14 per 1000 addresses
KickboxAPI for verification at the moment100 contactsFrom $0,008 per one contact
Mailbox ValidatorEmail address grading and scoring themIt is possible to check up to 100 addresses within 30 daysChecking a base of 5000 contacts and more it is $0,02 per 1 email
MillionVerifierAPI integration; chat support even with free plan; one of the most cost-effective10 addresses, if you enter and confirm the phone number, you can check another 200$0,00118 per 50 000 addresses
MailflossDaily base check; integration with other services7-day trial periodFrom $17 per month
QuickEmailVerificationA wide range of possible formats for downloading the client base; a wide choice of tariff plansAbility to check up to 100 email addresses daily$0.008 per address for a base of 500 to 3500 addresses
TrueMailSynchronization with CRM; focus on professionals1000 checkingsFrom $7 per 1000 addresses
XverifyPhone number verification; protection from crooks100 contactsFrom $0.01 for a base of 5 thousand checks
ZeroBounceFinding and adding user information to the report; generating detailed reports100 addresses per month$0.008 per email with a database of 2 to 5 thousand contacts

An example of checking the email validity 1

An example of checking the email validity 2The examples of checking the email validity

How to avoid collecting invalid emails

Contemporary and proven tools are used to properly collect a list of clients. A company needs to try to get more people interested in contacting them. The following guidelines help optimize the collection of email addresses:

Manage your own customer base

There are two methods of collecting email addresses: creating your own database or purchasing a ready-made one. The latter method is inefficient, as the ready-made database contains user contacts who do not know anything about your company or are just not interested in the offers. Therefore, this method is a waste of time and money.

It should also be noted that popular mailing services do not accept ready-made bases and block senders. Due to this, it is best to collect the addresses of potential buyers yourself, as well as to warm up their interest with newsletters.

Run regular email checks

Customers change, delete, abandon, forget, or even sell their email addresses over a certain period of time, for example, a year. Therefore, you should check your email list in special services and get rid of unnecessary emails.

Apply the double opt-in

Add double opt-in, so that customers confirm their registration and receive offers from you. There are times when mail is not confirmed, which means you should remove it from your list.

Add a link to unsubscribe from the newsletter

If customers get bored with your newsletters, they put the emails they receive in spam. To avoid this, add an active unsubscribe button, which makes it easy for a person to unsubscribe from your messages. This is good for the company, because it saves the company's reputation.

Use a subdomain

Instead of sending messages from the main domain, use a subdomain. This avoids getting spammed and improves the sender's rating. A subdomain is a specific part of the main domain. If your account gets blocked, you can simply create another one without losing your domain name.


So, as we found out, a valid email is a real and active email address. In this article, we've explored the mechanism of reactivating a customer base via validation. Let's summarize the general results:

  • Create your own database and monitor it regularly. Get rid of invalid emails and keep an eye on the sender's reputation.

  • Use validation checking online services. Choose the one that best corresponds to your company.

  • When creating an account to send newsletters to a database, take subdomains.

  • When collecting addresses, request email confirmation from the client. This way you'll get rid of invalid emails right away, and then you'll have proof that the customer allowed the company to send them personal emails.

  • Add an unsubscribe link so that the customer can unsubscribe from receiving your emails.

  • Remind customers of yourself all the time by sending them reactivation emails.







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