What is Email Lookup?

Email lookup, also known as either Email checker or Email verifier, is a very fast, highly accurate and free lookup tool that allows you, through the verification process in stages to determine the existence of email. The check-in process takes place through the following steps:

• First, our tool resolve host name (SMTP server) to IP address
  from Email that you are checking and then try to connect to that SMTP server via port 25 (it is standart Simple Mail Transfer Protocol port for sending mails).
  
  For example the hostname of the email [email protected] is mmxint01.1and1.com and it resolve to the IP address 212.227.126.206. If the connection is successful, our checker tool will start check your email using the verification procedure.

How does the email verification process work?

• The process of checking mail is done by sending SMTP HELLO command to other side (SMTP server) asking server to verify searched email address.
  Once SMTP server accept our request and our "question" then he let us know of Mail ID / Recipient is OK or NOT.
• The final step of the whole validation process is to show you the response from the SMTP server after the verification process is complete:
  "the host states that the address is valid or not."
  
  Once we get answer we disconnect from SMTP server.