The traditional “Yahoo Mail Classic,” the interface created in 1997, was preserved until July 2013. An enhanced version of Yahoo Mail released in 2007 included a new Ajax interface, drag-and-drop, improved search, keyboard shortcuts, address auto-completion and tabs. In May 2011, a new version of Yahoo mail that included improvements to performance, search, and Facebook integration became the default interface. In 2012, Yahoo introduced another webmail interface, redesigned with new versions for Windows 8, Android, and iPhone clients. In 2013, Yahoo released Yahoo New Mail, which prompted criticism from users, particularly because of the removal of certain features.
Yahoo Business Email is a combination of all Yahoo email services with features of the plus version and personalized domain name and email address. It includes unlimited mail storage and a quota of 10 email accounts. In December 2013, Yahoo Mail suffered a major outage during which 1 million users could not access their emails.