1. Segmentation: Even with a smaller pool, segmenting your list based on demographics, behavior, or purchase history can improve relevance and engagement. 2. Personalization: Use personalized subject lines and content to increase engagement. 3. Frequency: Finding the right balance in email frequency is crucial. Too many emails can lead to higher unsubscribe rates, while too few can result in lower engagement. 4. Content Quality: Ensure your content is valuable, relevant, and engaging to keep your audience interested.