Keeping your email subscribers engaged is always a challenge for nonprofits. Your supporters are dealing with inboxes that are not only full; they’re bursting. It’s estimated that over time, you’ll lose 1-in-4 subscribers to churn. These aren’t people who unsubscribe; they just ignore your emails. Before cutting them loose and eliminating them from your email list, however, try one more campaign to win them back: a re-engagement campaign.