The spate of law-suits between companies like RIM and Visto could soon be over, thanks to a mobile email standard which might support an open-source alternative.

"Things are about to happen rather quickly, and it should prove interesting for people like Visto and RIM," said Will Sheward, vice president of marketing at Isode, a long-established specialist in standards-based software for email and directories. In June, Isode will launch a new version of its standards-based email server software, which will support mobile email, and should be immune from legal attack.

The server uses Lemonade, a proposed standard from the Internet Engineering Task Force (IETF), which is also known as M-IMAP, since it is essentially a mobile version of the widely used IMAP protocol.

"If they really believe they own the rights, these companies could sue the IETF, but it would be a hard task to prove it," said Sheward. "It would be like saying our proprietary system has some of the same features as IMAP, therefore we own the IMAP protocol."

Once the basic principles of mobile email are embodied in open standard protocols, companies will - and should - concentrate on providing additional services over and above those protocols, said Sheward. "It would be a relief for consumers if they could worry about email functions rather than the latest lawsuit."

Lemonade based servers will require clients on mobile devices, but these will be produced by handset makers, he said, pointing to support for Lemonade from Nokia and Sony Ericsson (PDF)).

Further down the line, clients and servers could be built on open source lines, he said, and organisations like the public sector could help promote this approach, as they have with Linux and Open Document Format.

If good mobile email clients are available for all mobile devices, then buying a specialist client for mobile email would be as likely as buying a specialist PC to run email or any other generic application, said Sheward: "The Blackberry could go the way of the Wang word processor."

Mobile email standards have come on in leaps and bounds since a meeting in December 2005, when the IETF group and the OMA (Open Mobile Alliance) agreed on a common approach, and now have a standard which should be formally complete by the end of the year. Previously, OMA had been backing a different architecture based on its SyncML standard.

Lemonade, stands for "license to enhanced mobile oriented and diverse endpoints" an acronym which may be contrived, but states the case for standardising protocols and then encouraging innovation on top of them.

Readers wanting to know more about the current state of play in the mobile email market will be interested in the Techworld webcast, broadcast live yesterday, but available for viewing here.