A system state in which a single action or a series of actions are performed. A mode has an On condition and an Off condition. For example, an Outbreak mode under Symantec Mail Security for Microsoft Exchange might look like the following: Mode On condition: More than 30 email messages with the same subject line are detected in a period of 10 minutes. Action(s): Quarantine all emails with subject line , run LiveUpdate every 10 minutes. Mode Off condition: Less than 10 email messages with the same subject line are detected in a period of 10 minutes.