Maybe Suade is using a program "like" Email Address Finder (3.1 crack does not need the install file) which connects to an ISP's mail server and attempts to verify email addresses either by brute force or using a list of usernames that you give it. This method does not work on all ISP's as it did in years past, some ISP's will just block you after a few tries, other's will either verify the addresses as all being good or all being bad. There are some ISP's out there that this type of program will still work on, the list you get from it IS NOT can spam compliant because you are basically harvesting these addresses. However if you get enough of them, the list would be very good because all of the addresses are solid user's which would mean higher delivery rate, less bounce backs (if any at all) and more conversions.

Please note that this software will not work on all ISP's when trying to do it from your home/office because a lot of them now a days block the out going requests to connect to the MX servers of other ISP's. You can get a cheap dedicated in another country and run this thing day/night to get your email addresses if you choose to go this route. I on the other hand do not recommend it as it is highly illegal to send these addresses an email as it breaks the US Can Spam Act law.