Kishen is a serial Entrepreneur and Author. He wrote multiple books on Marketing and Growth and have helped startups grow their business.

Verify an Email Address: A Simple Guide to Validate an Email Address in 2017


Nobody’s a stranger in this world anymore, you are connected with everybody in this world with 3.5 degrees of separation. We all know so much about each other already, why can’t this be extended to e-mails as well? It should be.

If you are sending cold emails to potential clients and the mail bounces, you might get penalized and be treated as a spammer by email services. Now that’s a risk you shouldn’t take. So how do you always end up with a valid email address for a prospect? Let’s find out.



Email Verification Strategies


Strategy #1 – Simple and bulletproof way: Send them an email

Sign into any of the email services like Gmail and send a blank email to the prospective person. If you don’t get a Delivery Status Notification, it’s one of two things. Either :

  • The email exists, (Yay!) or,
  • The server is configured to be catch-all


Catch what? The SMTP Catch-all

A catch-all domain in simple terms means, the server of that company will catch any email sent to that domain, even a non-existent address and store it in a section called the catch-all. When this happens, you have no clue if it’s a legitimate email address or not.

Not a Catch-all domain, but might still be a problem

So there is a configuration that companies can use, where the mailer daemon can accept emails even if the recipient email address is invalid and automatically discard them. This happens without any notification sent to the sender. There is no way of


Strategy #2 – Email verification with Telnet

Hoboy, there’s going to be some tech coming your way, but if you are geek enabled, then this should be a breeze for you. Before we get into the nitty-gritties, let’s test our target email address, I vote for

Step #1 – Enabling Telnet or Putty

If you have Putty installed, you should be good to go, otherwise, you’ll need to enable Telnet.

Step #2 – Using the Command Prompt

Go to the Command Prompt and type the following (This command looks up the MX records of because that is our target domain. So if your target domain is something else, make sure you enter that in the place of You’ll get a list of the MX records, something very similar to this).


nslookup -type =mx


Answer: MX preference=30, exchanger = MX preference=20, exchanger = MX preference=5,  exchanger = MX preference=10, exchanger = MX preference=40, exchanger =


Step #3 – Sort through the MX records

Sort through the MX records and find the one with the lowest preference number. This is the record you’ll be targeting to send a test email.


Step #4 – Connect, Get Acquainted, Your Address, Recipient Address

Connect to the Server: The first step is to connect to the mail server. Use the following command

telnet 25


Get Acquainted: Enter HELO in the command prompt



Your Address: You need to enter your email address, but make it random, it shouldn’t be your actual address.

mail from: <>


Recipient Address: Enter the target email address, then one you are trying to verify. In our case it is

rcpt to: <>


Step #5 – Identify if the email address exists or not

If the email address exists, you’ll get an ‘OK’. If it doesn’t exist, you’ll get an error message like this.

  1. The email account you tried to reach does not exist
  2. The email account you tried to reach is disabled
  3. Or anything which is not “OK”.


Strategy #3 – Just guessing (Eenie, Meenie, Minie, Mo)

We’re all through naturals at guessing. And for finding emails, guessing has been the go-to strategy for a long time and still is, in many cases. But adding a bit of science and research to your guessing can increase the odds of getting it right. Sometimes a way like this is better than using an email verification software


Template and Rapportive

Generally, companies have email formats and it is pretty straight forward. So if you have a list of prospects, a good way to test is to try a bunch of these formats. -- Ex :
firstname -- Ex: -- Ex: -- Ex: -- Ex: -- Ex :


One important point to note is also the country of origin of the prospect. Different countries have different ways of treating a person’s name and the best way to find out the general format is by looking at examples or even better is to ask a bunch of people from that particular country.

After coming up with a set of options for the email address, use Rapportive to check if it’s legitimate. Download the Rapportive plugin from the Chrome Store and refresh your Gmail. Then compose a mail testing your email combinations. When you hit the right one, you’ll see the details of the person on the right like the image below. This is when you know you’ve hit jackpot! 


Strategy #4: Use

We have to do a shameless plug! But hear us out! We are in this business and we have a kickass solution. is a big data tool that verifies emails through various datasets. It is not a guess based tool.  


  • We have a verified over 100 Million emails and have a delivery rate of 90%.
  • This is a constantly evolving tool that is just getting better by the second. It also automatically removes false records.
  • The powerful algorithm sifts through over 100 trusted datasets to find the verified email address you are looking for.
  • There is also an option to Bulk Search. If you have a list of prospects, just upload them and wait for our notification.
  • Our Chrome Extension lets you find email addresses right from your browser
  • We also integrate with tools like SalesForce, MailChimp, Zoho and Pipedrive.

You can try it for FREE here. It’s the best free email verifier out there. Some nice words from some happy users.



To Summarize

There are ways that are slow or fast to find emails and there are ways that are accurate and there are ones that are inaccurate. But as a business, you’ll need a way that is fast and accurate. You’ll need something seamless. You’ll need something that is backed by deep technology that gives you accurate results. Trust me when I say this, we don’t believe in tooting our own horns, but if you are serious about finding valid email addresses, then is a great solution.

For those of you who want to just check out one or two email addresses you could try the strategies that we’ve mentioned above or a better way is to enter it in our free email checker engine here.