What are the e-mail checkers and who might consider them useful

In the world of total digitalization and direct marketing sales (through e-mail), the need to know that some email address is alive becomes vital. Today, we are considering the issue of special online tools, which can check emails – they are called email checkers. To take some basis for the consideration and to operate with the real result of email verification, we’ve picked the email checker (which obviously makes the united holding with at least two other email checkers: and based on the similar approach to pricing and naming of their tariff plans).


What is the e-mail checker

An email checker is an online tool, which allows natural persons, companies, and any kind of groups and businesses to verify email (single or batch of emails). During the email verification, depending on the specific tool, a user is informed about various check results (some email testers only deliver 1 field of data like does this email exist or not, others may deliver dozens of fields of data). The email checker delivers 4 fields:

  • Exists (Y/N)

  • SMTP (+/-)

  • SMTP Catch-all (Y/N)

  • Trusted rate (in %) – it is also said that 60% and higher trusted rate means that the email is a nice one. 

The biggest part of email checkers gives the possibility to all users, even unregistered, to check about 10 emails during some period – this can be an hour, day, month… This checker here allows 10 checks per month. If a user registers as a company and enters the payment data (attaches a credit or debit card), then the number of free checks is 100 per month. If there is no payment data entered, the number of checks in a free email verifier reduces to 10. 


How e-mail checker checks if email is valid

Now let’s look at the technical side of work of email address verification. Depending on a tool you’re using, there might be slight variations of actions but the main actions are all mainly the same.

  1. Checking the given email name to contain all necessary characters, structure, and not to look like a dummy one (created by a monkey)

  2. Pinging the email server to confirm it exists in the first place.

  3. Connecting to the mail server and exchanging a sequence of commands, which allows finding out the needed information about an email address. At this stage, it is defined whether this email exists for real, takes question and gives answers (and they differ depending on the type of the questions, not all the same, which otherwise would mean that this email is a junk and you should not send there any mailing), and behaves like a normal e-box is expected to.

  4. Connecting to some outer sources of data like social media or email data storage places (like blacklists and white lists), which would inform anything about the checked e-mail additionally.

  5. Forming an answer and submitting it to the user. 

This scheme does not mean 100% assuredness in the fact of existence or non-existence of any checked email but it gives more than 90% outcome. The thing is that a complete assuredness in the check results cannot be reached because far not all mail servers play using the same rules. Some of them don’t answer the given questions, some don’t give any nice feedback, and some can’t tell for sure if they have a checked email on their server or not. Despite there is no total assuredness, practice shows that after using email checker’s services, the database of e-mails is cleared at 90% and more. So the bounce rate of letters you send onto them is as max as 10% (some email checkers even claim that the reduction of bounce rate gets down to just 2.5%).


What are the benefits of an e-mail checker?

And here comes the point of why we need to know how to check if an email is valid:

  • To lower the bounce rate – we’ve told about that just now. If email checkers can increase the delivery rate from around 20%-50% to 90%-97%, it means they are useful. Now imagine you’re working not with dozens or hundreds but with hundreds of thousands or millions of emails. And if your sending list is that big every month/year, you definitely need to do the email verification to cleanse the database prior to sending. Corporate clients are offered special subscription rates (approximately in the range from 0.003 to 0.005 dollars per 1 checked email). At, you can also ask to design an individual price if you need much more than a million to check.

  • To purify the database. It is not a secret that the delivery of each letter costs some money. It is always better to send 100 letters and receive a 90% delivery rate (paying to a company-sender and to a company-email checker) than to send 100 letters receiving a 20% delivery rate and paying only to a company-sender. All in all, it turns out cheaper to work with a cleansed database.  

  • You may keep your email database up to date, which is important if you deal with many clients using a CRM system or something like that.

  • Saving your time and efforts by writing letters to clients, who may not receive it may be a small thing but it still is input into your business.

  • Not only you know, which e-addresses are not working or not existing but it is also possible to clean the database from bots (which are mostly boxes that only resend all received emails to other boxes), blacklist and spam addresses (the so-called email spam test). 

  • Also, you won’t get into the spam bases your own if you send lesser letters to only verified recipients.

Who might find an e-mail verification useful tool?

Now, logically to conclude who are the main users of email checking online tools:

  • Datacenters

  • Sellers working in the area of direct sales (through emailing)

  • Individuals who want to check email online to know whether to spend time on writing a letter to somebody who may never read it

  • All types of companies who not only sell through mailing but who make their clients stay up to date with company news and send special offers or discounts

  • Call centers, sales centers

  • Coupon sites.


Is there any API that developers could use?

An API is the program interface, which is specifically designed to connect with the ‘processing core’ of some email verifying software (in so-called thin or thick clients). Typically, an API for an email address checker is made of several strings of code, which make it possible to connect to an email checker and make bulk queries for the check. The API can be realized as a separate installable program – usually, an app for a PC or mobile/tablet – in case if the company’s programmer will not work out the technical integration of the company’s programs using the given open code.

API is mainly needed to process batch checks in order to check if the email is real – up to millions of strings of data during one request. 


Frequently asked questions

What are the limits of free lookups?

Usually, not more than several of them per 1 day or month. The checks are, as a rule, connected with 1 IP. By switching the IP, it is possible to run more checks. But don’t think that you will be able to run thousands of checks in this way – still, it takes significant time and, eventually, that much data requires a subscription in order not to waste your efforts.


Is any data stored about the checked e-mails by the Gmail checker? 

No. At least, not for long – it is erased at once as the check email is over and the results are delivered to users. During a single-address check, this can take seconds. During a bulk check, the temporary storage can take minutes or hours.


Do the checked email address owners get informed about the email validation?



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Common Questions About Email Verification

You may still have some questions about the email verification process. The following are some of the more common FAQs. The answers here will help you better understand the full value of our tool. If you still have questions after reviewing this section, feel free to visit our Help Desk or contact our Customer Success Team; we’re always happy to hear from you.

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Other Useful Steps to Improve Email Deliverability

Making sure your emails are properly delivered is important. Thus, senders should also consider taking these steps before sending emails to followers:

By taking these steps and using NeverBounce, you’ll be much more likely to consistently deliver emails. Luckily, our single email checker is both thorough and efficient. All you have to do is integrate it with your platform to ensure anyone who signs up for your newsletter is actually providing a valid address. This is important in the competitive field of email marketing.

Don’t let a poor sender reputation prevent you from reaching your followers. Create your NeverBounce account and start using our email and bounce checker today!

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