The University of Arizona uses a system called UAlert to send messages to registered users about emergencies on campus.

On Tuesday, that service sent an email to more than 800 people about a possible threat in the Administration Building. However, that same email had already been sent back in March. It stemmed from a report from UA police about a man with a rifle on campus.

Chris Sigurdson, a UA spokesman, said this week’s emails were a false alert.

"The company that provides the technology underpinning for UAlerts put an old server back online without wiping it clean, and when that server got fired up it began sending alert messages to UA employees," Sigurdson said. "One of the employees called UA police who contacted Omnilert, the technology provider. They took the server offline as soon as they could and stopped the transmissions.”

A spokeswoman from Omnilert said the company is looking into the incident and preparing a report for the university. The company services about 13,000 organizations.