Kendo - 9:46 pm on Mar 18, 2013 (gmt 0)
That list probably includes the top 20 most popular free mail services. On one site we have a sign up form for a free service and the subscriber needs to validate their email. So many people have so many different email addresses... if they don't receive their confirmation mail they sign up using another email address and so on. Some don't even remember their correct addresses.
Billions of dollars worth of data wasted in spam traffic and all they have to do is stop providing free mail services. What's wrong with the mailbox that one's ISP provides with their internet service?