What is an Email Verifier?

Email verifier a free online tool to lookup and verify email addresses. Our tool will take you through the whole lookup process, step by step, instead of a simple result without any records, of whether the email address is valid or not. You will be able to see what the verification process looks like leading to the final result and a conclusion that will tell us whether the email is valid or not.

Verified stages of the Email Lookup process

The lookup process, in short, takes place through the following stages:

  • 1) Enter the email address you want to verify in our email verifier tool. In this example, we will use a CPS edu email address [email protected] that uses the Google mail service
  • 2) To be able to connect to the destination SMTP server via port 25, we need to know its IP. The second stage is to determine the IP address of the entered email via converting the host to IP that is also the SMTP server of the entered email. In this case it is ASPMX.L.GOOGLE.COM:

    Connection to SMTP Server

    Resolving host name "ASPMX.L.GOOGLE.COM"...
    Connecting to IP/host address ""...
  • 3) The third phase is testing SMTP communication by sending a standard greeting Hello from our server. As can be seen after a successful connection, Google SMTP informs us via SMTP codes 220, 250 and 354 that it has performed an action on our inquiry about the validity of the requested email and that the email is ready to receive messages

    The Verification Process

    S 220 mx.google.com ESMTP i4si3082170iov.52 - gsmtp
    C HELO ip-lookup.org
    S 250 mx.google.com at your service
    C MAIL FROM: <[email protected] >
    S 250 2.1.0 OK i4si3082170iov.52 - gsmtp
    C RCPT TO: <[email protected] >
    S 250 2.1.5 OK i4si3082170iov.52 - gsmtp
    C DATA
    S 354 Go ahead i4si3082170iov.52 - gsmtp
  • 4) The fourth and final phase is based on the verification process from the third phase, so verifier can determine whether the requested email is valid or not. In this case, Google SMTP has notified us that the mail [email protected] is valid so:


    This host states that the address is valid.

Type the number:

Check the validity of Gmail, Hotmail, iCloud, Outlook, Hey email addresses

You can check email account as well as availability from any provider with our email checker using a number of lookup processes including all kinds of popular free email services like Google Gmail, iCloud, Protonmail, Microsoft Hotmail, Outlook, Hey, Zoho etc.. The only exception is Yahoo which does not always respect the email verification process so the Yahoo SMTP server often gives an invalid response. If you are check Yahoo email as well as other popular free emails that use Yahoo SMTP server like AOL or Rogers take the result with caution.