Spending on messaging applications will double to nearly $2.4bn (£1.3bn) by 2007, with instant messaging the big growth area.

Research conducted by IDC predicts that email servers and related products will remain the strongest revenue generator in this market for some time to come.

But the strongest growth will come from instant messaging, instant messaging management and presence applications, whose revenue is expected to grow at a compound annual growth rate of nearly 30 per cent from 2002 to 2007.

Robert Mahowald, research manager in IDC's collaborative computing group, said messaging applications are at the heart of business collaboration.

"To extend their use, businesses need to be more strategic in their thinking about how older technology like email can be updated to meet newer needs like regulatory compliance, and how newer products such as enterprise instant messaging and unified messaging can make information workers more productive," he said.