Amstrad Em@iler
2000-2011
The Amstrad E-Mailer, sometimes written as Em@iler, was an early attempt at an all-in-one telephone/email messenger with Internet access, basically an early smartphone. But this not-so-smart-phone had some major drawbacks: users were charged per minute and email, all while enduring intrusive on-screen advertising. Despite widespread criticism and poor sales, Amstrad continued pushing out new versions until the service shut down in 2011.
Additional info:
The Telegraph - The biggest technology flops in history
A horrible commercial: