The US Department of the Interior has moved its e-mail business to Google, which sued when the agency gave Microsoft a five-year $59.3 million cloud-based e-mail contract in 2010 claiming the department's research was "stale" and Microsoft's security wasn't certified for government use.
It's going with Google Apps for Government and Gmail instead. It will cover upwards of 90,000 seats.
The agency's been reconsidering its original decision since late last year.
The deal is worth $34.9 million over seven years to Google and its reseller Onix Networking.
Microsoft said it "will engage with our partners and DOI to review and understand the reasons for this decision."
Microsoft lost the General Services Administration and its 17,000 seats to Gmail two years ago.