It has become the corporate equivalent of the iPod: the BlackBerry mobile email device, from Canada's Research in Motion (RIM), has become the ubiquitous business tool. And that certainly shows in RIM's numbers.

In May 2005 the company announced it had signed up its 3 millionth BlackBerry subscriber, having added the previous million in just six months. As recognition of that seemingly insatiable demand, investors cannot get enough of RIM's stock, a fact that has pushed its market capitalisation to over $14 billion.

But with success has come envy – and plenty of imitators. While RIM has enjoyed being the default choice for mobile email, its competition is about to become a whole lot fiercer.

Mobile operating giant Vodafone (today a major vendor of BlackBerry devices and services) recently inked a deal with Visto Corp to deliver a new ‘push' email service, similar in concept to the BlackBerry. But, importantly, such mobile email services will be sold under the operator's brand and will support a broader range of handsets – an appealing prospects to users frustrated by the RIM-specific catalogue.

Mobile operators offering email services today pay service and support fees to RIM, which exerts tight controls over the number of available devices. That has competitors lining up to offer alternatives. Furthermore, Microsoft is waiting in the shadows, preparing to unleash its assault on the mobile email market.

Given these storm clouds, RIM's founder and co-CEO Mike Lazaridis is remarkably sanguine about the threat to his company. "There's a massive amount of work that went into the BlackBerry; the whole concept of a ‘push' technology was different. And we built in security from the beginning. Competitors aren't going to find that mobile email is something they can just do," he says.

Lazaridis underscores the security aspect. The BlackBerry might not have received the kind of endorsement the US President bestowed on the iPod when he said he was a user, but Lazaridis claims that the BlackBerry is widely used within the White House. "We're trusted by the government, the US military and the police because we are secure."

As more businesses look to equip staff with mobile devices, the BlackBerry's strength is that it does not open up weak spots in corporate firewalls, explains Lazaridis – the devices do not dial-in through the firewall. RIM has also improved its ability to remotely lock and wipe lost devices.

And while competitors have still to demonstrate they can match this level of security, Lazaridis has his eyes fixed on new markets. "We've been doing mobile email for five years now. Now we can take that further. We can connect into corporate data, access back-end systems."

Already, Yorkshire Police are using BlackBerrys to access the central Police National Computer. And Lazaridis is confident that others will want to connect to Siebel, SAP or Oracle applications using the BlackBerry: his vision is for the small handset to become an alternative to the corporate laptop.