Email list hygiene is crucial for email marketing success as it ensures messages reach the intended recipients, maximizes campaign efficacy, and safeguards sender reputation. Maintaining a clean list requires identifying and removing invalid addresses, duplicates, typos and inactive subscribers through regular data scrubbing with automated and manual review. It also requires permission-based marketing, easy unsubscribe options, email verification services, re-engagement campaigns, and monitoring metrics to identify engaged subscribers. Dedication to email list hygiene guarantees email marketing efforts will thrive by consistently delivering messages to the right inboxes.