Several types of data are at risk in email marketing, including: - Email addresses: The most basic and essential data, often targeted for spam or phishing attacks. - Personal information: Names, addresses, phone numbers, and other personal details that can be used for identity theft. - Analytics data: Information about user behavior, preferences, and engagement, which can be misused if accessed by unauthorized parties. - Transactional data: Purchase history, payment information, and other financial data that can lead to fraud.