The Department of the Interior has chosen to move its e-mail services to the cloud using Google’s government apps.

It’s a big win for Google, which has battled Microsoft for federal government e-mail contracts. Google has won contracts to serve as the e-mail service for, among others, General Service Administration and the National Oceanic and Atmospheric Administration.

In 2010, Google filed suit against the Interior Department, claiming that the agency had favored Microsoft in its bidding process. As The Washington Post reported, Google had pointed specifically to the fact that the bidding guidelines called for inclusion of Microsoft’s Business Productivity Online Suite. The company argued that the provision was ”unduly restrictive of competition.”

In a release, the Department of the Interior said that it will use Google Apps for Government for e-mail, as well as giving its workers the option to use Google Docs, Calendar, Sites and the audio and video chat features.