Hy EMS automatically extracts mail server addresses from a DNS , if it finds one or more email server addresses then it connects to the SMTP server using mulitiple threads and works like a STANDARD SMTP server . It sends a standard SMTP command to the server , and verifies the server's answers . If the server says 'Yes there is an email address here like that'' then EMS knows the verified email address exists and that address is added to the file of valid email addresses that EMS is building. EMS can quickly find a lot of real email addresses.