The move bolsters Cisco’s strategy to expand into the office software market by adding e-mail and calendar services to its existing roster of so-called enterprise networking features. PostPath, based in Mountain View, Calif., develops Linux-based software that gives corporate customers an alternative to Microsoft’s Exchange system. PostPath says its e-mail servers are compatible with a nearly all business systems, including Apple (AAPL) and its iPhone. 

Cisco, in announcing better-than-expected quarterly profits but a lower growth forecast, said earlier this month that it planned to make acquisitions in adjacent markets outside its core business selling Internet equipment.

With Google going door-to-door trying to sell its business software to Microsoft clients, this latest move by Cisco into e-mail isn’t necessarily a great comfort to the Redmond, Wash. giant. Given Cisco’s dominance in corporate IT gear, there is potential for Cisco to offer an alternative to Microsoft Exchange.

Cisco plans to add PostPath’s applications to its Web-based services, also known as “cloud computing.” Software providers have for years been looking for ways to let business users access their desktop computing tool wherever they happen to be. This way employees could collaborate on tasks using features like instant messaging, video conferencing or document-sharing services.

Microsoft’s quest to extend its desktop software dominance to the Web was a driver behind its failed bid for Yahoo earlier this year.