Founded in 2000 with the goal of providing low-cost mobile phones designed to carrier specifications, Sendo grew into a significant operation. By 2004 the company was shipping 5 million handsets annually to locations in Europe and, to a lesser extent, Latin America and the United States.

Moreover, Sendo clearly had its eyes on the smartphone market. The company initially planned to sell smartphones running Microsoft's Windows Mobile platform, but the company made a very public split from Microsoft just weeks before commercially launching Windows Mobile phones in order to build smartphones running Symbian. The Sendo X represented the pinnacle of Sendo's high-end phone efforts: the GPRS tri-band phone incorporated the Symbian OS and Nokia's Series 60 software, which was cutting edge at the time.

However, Sendo wasn't able to generate the revenues it needed to stay afloat (Sendo reported revenues of $420 million in 2004). And perhaps more importantly, the company in lawsuits alleged that Ericsson and the European Telecommunications Standards Institute were actively quashing competition in the handset market with unfair royalty rates.

The end of Sendo came in 2005 when Motorola (at the time the world's second largest mobile phone maker) agreed to acquire the research-and-development operations and the patent portfolio of Sendo. The action brought to a close Sendo's ambition to challenge the heavyweights of the handset market.