The Army said it expects to complete migration of both classified and unclassified email to an enterprise cloud operated by the Defense Information Systems Agency by April 2013.
Mike Krieger, Army deputy chief information officer, said in a blog post that the service resumed migrating its unclassified email accounts to the DISA cloud on Monday, after a delay at the start of 2012 due to a review mandated in the 2012 National Defense Authorization Act.
The Army sent lawmakers the results of that review on Feb. 16, Krieger said, enabling migration to resume this week.
The service already has shifted 310,000 unclassified email accounts to the DISA cloud and Krieger said it plans to start moving classified accounts this summer.
The Army started its enterprise email project in February 2011 and initially planned to shift 1.4 million unclassified and 200,000 classified accounts by the end of that year.
DISA also has agreements to host email accounts for the Africa, European, Northern, Strategic and Transportation commands.
Teri Takai, the Defense Department's CIO, told a hearing of the House Armed Services Subcommittee on Emerging Threats and Capabilities on Tuesday that the Army, Air Force and DISA are developing a Defensewide enterprise email system.