Why should I segment my list by engagement level?

Engagement-based segmentation is the single most impactful segmentation strategy for deliverability protection. Mailbox providers heavily weight recipient engagement when filtering mail. Sending to subscribers who ignore your emails drags down your aggregate metrics, signaling to Gmail and Microsoft that your content isn't wanted—which affects even your engaged subscribers.

Beyond deliverability, engagement segmentation drives efficiency. Why send the same volume to someone who opens every email and someone who hasn't opened in six months? The engaged subscriber wants more; the dormant one might want less (or none). Matching frequency to engagement level respects subscriber preferences implicitly.

Engagement segmentation protects your best relationships from your worst. Without it, your unengaged subscribers poison the well for everyone. With it, you can send confidently to engaged audiences, nurture the uncertain, and gracefully sunset the departed. It's not about excluding people—it's about sending the right amount to each person based on their demonstrated interest level.