Enterprise push e-mail first caught on with the BlackBerry, which became indispensable to many executives who wanted to easily stay connected outside the office. Despite the arrival of competitors such as Visto and Good earlier in this decade, that device and its companion BlackBerry Enterprise Server still dominate the business world.

"I don't think they've given up a lot of market share," said In-Stat analyst David Chamberlain. Yet there is still a chance for alternative providers to gain traction among consumers, the fastest growing part of the smartphone market today, he said. There may even be a place for the light e-mail clients from the smartphone world in small PC alternatives such as netbooks and MIDs (mobile Internet devices), Chamberlain said.

The deal probably will add to Visto's war chest of patents, Gartner's Dulaney pointed out. Intellectual property has been a key weapon in push e-mail rivalries. Among the patent disputes over the past several years, Visto has sued Good, RIM and Microsoft, and Seven has sued Visto, though the two companies later settled the dispute. In 2006, patent holding company NTP won a US$612.5 million settlement against RIM after a widely criticized lawsuit that threatened to shut down RIM's service in the U.S.