Assessing your email list quality involves several metrics: 1. Open Rates: The percentage of subscribers who open your emails. 2. Click-Through Rates (CTR): The percentage of subscribers who click on links within your emails. 3. Bounce Rates: The percentage of emails that were not successfully delivered. 4. Unsubscribe Rates: The rate at which subscribers opt-out from your list. 5. Spam Complaints: The number of subscribers who mark your emails as spam.