How the Email Validate Tool works
The Email Validate tool is intended to be used to validate an email address.
This is done by direct communication
with the mail exchange (MX) machines for the target domain. Two
testing modes are used: email address VRFY test and the RCPT test.
These will help you determine whether the email address is active
and helps administrators check for proper email server security.
Email server username/password authorization is also included.