The practice of maintaining and optimizing the quality of an email list by regularly cleaning and updating it to ensure accurate, deliverable, and engaged recipients. Email hygiene involves various tasks such as removing invalid or inactive email addresses, correcting typographical errors, and managing unsubscribes and bouncebacks. Good email hygiene helps improve deliverability rates, enhance campaign performance, and protect the sender’s reputation by reducing the risk of sending emails to non-existent addresses or spam traps.