In email security, quarantine refers to the process of isolating incoming messages that are suspected of being malicious, spam, or otherwise harmful. Instead of delivering these emails directly to users’ inboxes, the email security system redirects them to a separate quarantine folder or area. This prevents potential threats - such as phishing attempts, malware, or unwanted spam - from reaching end users. Administrators or users can review quarantined emails to determine if they are safe or should be deleted. Quarantine helps reduce the risk of security breaches and ensures that only legitimate emails reach their intended recipients.