Sending terms of service (TOS) emails to unsubscribed users is generally discouraged due to legal risks and potential damage to email deliverability and sender reputation. While TOS updates might be considered transactional or service-related messages, anti-spam laws like GDPR and CAN-SPAM often require consent and honoring unsubscribe requests. Sending emails to unsubscribed users can lead to legal issues, increased spam complaints, and dropped domain/IP reputation. Experts recommend segmenting email lists, respecting user preferences, and exploring alternative communication channels like web banners. Legal consultation is crucial to ensure compliance.