A good spy software may help you.AllSpyMonitor can keep you informed of their emails, including web-based emails like Hotmail, AOL email, Gmail, Yahoo mail and hundreds of others.For more information:http://www.allspymonitor.com/feature.htm��
Why not use some professional employee monitoring software ,we have use one in our company,It s much safe for company business Information.http://www.pc-remote-monitoring.com http://www.employee-computer-monitoring.��http://www.employee-activity-monitor.orgHope this can help you .
A keylogger.