The governor's Office of Information Technology estimates the move will save $2 million per year.
Currently, state agencies use a hodge-podge of 15 different email systems, meaning the state lacks some basic functions most businesses take for granted.
State workers can't simply look each other up in their email systems, they have to rely on business cards.
"This move to a unified email system will save taxpayer money and put all state employees on one communication platform," Gov. John Hickenlooper said.
Most state employees will keep their current email addresses, though some unprofessional-looking addresses will be changed.
For instance, some workers in the state Department of Revenue have email domain names that read "@spike.dor.state.co.us" because the department has an old email server in its network named "spike."
The contract with Google is designed to cut back on the need for infrastructure. The state currently has 33 data centers full of server equipment, with plans to reduce the number to just two data centers.
Google's mail system is "cloud based," meaning that Google's servers handle the workload and the state's official email can be accessed from any computer with an internet connection.
The state handles plenty of sensitive data, but officials say they've thoroughly reviewed Google's security measures.
"It's hugely important," Colorado Secretary of Technology Kristin Russell said. "We would not be making this decision today if we didn't feel confident that they met the security requirements that we had."
The state hopes to have all of its workers switched over to Google mail by the end of 2012.
Several other states have already switched to the service and it's already in use by some local governments and universities in Colorado.
(KUSA-TV © 2012 Multimedia Holdings Corporation)