Definition
A sunset policy establishes when and how inactive subscribers are removed from your active mailing list. Subscribers who have not opened or clicked an email within a defined period — typically 90 to 180 days for standard programmes, 12 months for newsletters — are moved to a re-engagement sequence or automatically suppressed from future sends.
Sunset policies protect sender reputation by removing addresses that drag down engagement metrics. Mailbox providers increasingly factor engagement into deliverability decisions, meaning low engagement rates can cause even your most active subscribers to miss emails. A well-executed sunset policy is essential for sustainable email programme health.
Sunset Policy Stages
| Stage | Timing | Action |
|---|---|---|
| Monitoring | After 60–90 days of inactivity | Tag subscriber as "at risk" |
| Warning | After 90–120 days | Send re-engagement email asking if they still want emails |
| Incentive | After 120–150 days | Offer an incentive to re-engage |
| Final notice | After 150–180 days | Last chance email with clear unsubscribe option |
| Sunset | After 180 days | Suppress from active list or move to restricted list |
Best Practices
- Define your inactivity window based on your send frequency — send more = shorter window
- Implement a re-engagement sequence before sunsetting (typically 2–3 emails)
- After sunsetting, move subscribers to a suppressed list rather than deleting them
- Never email sunset subscribers again unless they explicitly re-subscribe
- Document your sunset policy and apply it consistently
- Review and adjust your policy quarterly based on programme performance
- Consider a shorter sunset window (90 days) for high-volume programmes
Related Glossary Terms
Blocked Contacts
Blocked contacts are email addresses that have been prevented from receiving future communications due to hard bounces, spam complaints, or explicit opt-out requests, maintained in a suppression list for compliance and list hygiene.
Email Bounce Handling Automation
Email bounce handling automation uses automated workflows to classify, score, and suppress bounced addresses, protecting sender reputation through progressive suppression rules and real-time monitoring.
Email Consent Renewal
Consent renewal campaigns restore permission to email subscribers whose consent has expired under GDPR regulations, typically achieving 10-30% renewal rates.
Email Delivery Failure
Reasons, diagnostics, and solutions for emails that fail to reach the recipient's inbox, including hard bounces, soft bounces, and blocks.
Delivery Rate
Email delivery rate is the percentage of sent emails that are accepted by the recipient's mail server, distinct from inbox placement rate which measures how many reach the inbox.
Email Dormant Subscriber
A dormant subscriber has not engaged with emails for a defined inactivity period, typically 90-365 days depending on industry. Dormancy classification triggers suppression and re-engagement activities.
Frequently Asked Questions
Yes, but these are subscribers who are not engaging anyway. The short-term loss in list size is offset by improved deliverability, better engagement metrics, and more accurate reporting. Sunbscribed but unengaged subscribers do not contribute to revenue and actively harm your programme.
Customer status should override standard sunset policies. A paying customer who does not open emails is still valuable. Keep them on a minimal-touch list or use an alternative channel to re-engage them. Sunset policies should apply to non-customer subscribers or confirmed non-engaged contacts.