Yahoo! Mail
Yahoo! Mail is an email service launched in 1997 through the American parent company Yahoo!. Yahoo Mail provides four different email plans: three for personal use (Basic, Plus, and Ad Free) and another for businesses. By December 2011, Yahoo! Mail had 281 million users, making it the third largest web-based email service in the world. Since 2015 its webmail client also supports managing non-Yahoo e-mail accounts.
Dada Mail
Dada Mail was initially written in December 1999 and released as version 1.0 in January 2000, between Justin's first and second semester at the University of Colorado at Boulder. Its original name was Mojo Mail, a name that came to Justin after having a dream about making a successor to the Majordomo program, after struggling with that program's email-based interface for a non-profit client.