Email Checker

Definition and principle of work of email checkers explained

It is an existing practice not to show your real email to anyone or to do it as little and efficient as possible. That is why people and companies tend to type in not real or one-day emails to all possible online forms that gather emails from them – from landing pages to registration on various websites. Also, emails tend to become obsolete with time, as their users change e-addresses or forget about using them. All these situations negatively affect the delivery rate to those emails. But there is a way out of this and we’re talking about it today – email checkers.


What is an email checker?

Every email checker is an online (and very seldom – offline) tool, which verifies the validity of emails submitted to it. It is designed as a simple-interface tool, which usually delivers two types of checks: single and bulk. During the single check, you can type in or copy-paste the email, which you’re interested to check and press the button. The tool will tell you in a short while whether this email is right or wrong. Another check, a bulk one, is necessary when there is a list of emails to check email (tens, hundreds, thousands, and even millions). It is possible to upload the list or copy-paste strings of e-addresses into the verify email field. The system will provide the result to you in seconds, minutes or hours – depending on the number of checks that need to be done.

The users of such tools can be natural persons and legal entities. 


How email tester works?

There is such a technical background of how a tool works:

  1. Syntax check. At this stage, it is checked that an email has the approved syntax like ‘[email protected]’ and no part is missing.

  2. Dummy check. Although you might have encountered such e-addresses like ‘[email protected]’, most often, they do not work as regular e-addresses of anybody and are used to make spam (email spam test), phishing, or can belong to bots. So, there is a number of criteria, which make any email address checker to say whether dummy check is passed or not during the check if the email is valid.

  3. DNS lookup and SMTP email address verification. At this stage, email verification tools connect to the email domain and verify its existence and the ability to cooperate. Then they start to exchange a sequence of commands, which make an email checking tool to say:

    • If this domain exists in the first place

    • If it accepts all e-letters coming to it disregarding the existence of a specific email address on it or not

    • If this domain and indicated email have ever been spotted in spam sends

    • If it is a one-time or fake emails generator

    • If senders can trust this domain (for instance, 100% trust to Gmail checked address but 0% trust to anything like ‘’ domain).

  4. Additional checks may be done on how to check if an email is valid: like gathering information about this email online, looking if it is connected to some social media accounts or job profiles, which significantly increase the level of trust.

  5. After checks are done, the report is being formed, which appearance will differ across email verification tools. Some only may tell ‘Ok’ or not ok, while others give dozens of strings of verification results, totally exposing the job done to check email online. 


Who could find an email checker useful?

There is a wide list of those users, who will find email checker of use:

  1. Companies, which have email marketing in the core of their activity and totally dependent on the delivery success rate

  2. Private individuals, which want to stay in touch with their friends, relatives, colleagues, and associates (it will be especially useful for those who have hundreds of connections and don’t have a secretary to manage everything)

  3. Freelance and IT specialists who offer their services

  4. Online shops and other types of businesses, which collect emails of their clients and visitors to send them informational letters or turn prospects to clients

  5. Companies, which are contractors of other companies or individuals and send many emails on their behalf

  6. Anyone who wants to keep their clientele’s base up to date and to decrease the emails’ bounce rate. 

What about API for developers?

Some email checkers offer API (Application programming interface), while others do not. In order to confirm the availability of API, you should take a look at the site of a specific email verifying software.

For instance, the offers its API (it is submitted with extensive explanatory documentation). Also, there are separate IT solutions, which are offered by third-party companies, offering the API specifically fitting the needs of many email checkers. One of such IT solutions is located on website. 

In addition to APIs, there may be separately elaborated applications for Windows, iOS, and Android – paid or free. 


What are the benefits of using an email checker?

The basic benefit of using email checker is decreasing the bounce rate of checked emails during the e-marketing company. Some email checkers promise to give the accuracy of check up to 99.9%, while others are less optimistic, offering about 90% in the end result. Additional advantages are:

  • fast checkup thanks to free email verifier

  • a possibility to keep the database up to date in between email marketing campaigns or just in case

  • saving time and budget during the mailing campaigns

  • control your delivery goals and meet the expectations of your company’s management

  • a possibility to purge high-risk emails, which may spoil the picture for you as your sender’s address could be added to spam lists after sending a letter to a highly risky address

  • a possibility to identify (during the further analysis), which clients in your database provide you with fake or otherwise irrelevant email addresses, to exclude them from your future campaigns and programs. 


Frequently Asked Questions

Do all email checkers work the same?

No, they all have different logic as they all are developed by different people. The number of performed checks differs, as well as the logic and degree of every check, the impact of every check to the final result in the report, and more things akin. This may result in diametric results when one email checker says the address is fine, whilst another says it is non-existing or something like that. 


If an email address owner informed about being checked?

No, nobody knows that his or her address is checked during the lookup. Also, there are no emails sent on or from the checked email during the check, as this entire procedure is done as ping.


Are email checkers free?

You can check does this email exist or not for free several times with the same email checker. But to check if the email is real more than 10-20 times during a day/week or month is usually impossible without paying. To withdraw these limits, users have to pay. The payment amount depends on the subscription plan of each email checker.


Is the email address stored anywhere after it will have been checked?

The majority of email checkers store emails only during the time of check, in order to make it possible to conduct the check and form the report about it. After, it is deleted immediately or in a short while. However, you have to understand that no email checker, no matter what it says on its webpage, is capable of guaranteeing you that. So, there is always a possibility that some or all checked e-addresses after email validation will get into the hands of phishers or spammers.

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