Symptoms#
- Messages landing in spam despite previously good placement
- Bounces mentioning policy, authentication, or reputation
- Provider dashboards showing a drop in reputation or authentication pass rate
Diagnosis steps#
- Confirm the configuration is live: query DNS from an external resolver and check the sending platform's settings page.
- Send to a seed mailbox and read the full headers, especially Authentication-Results.
- Compare the domains in From, Return-Path, and DKIM d= for alignment.
- Check provider dashboards (Google Postmaster Tools, Microsoft SNDS) for reputation and error rates.
- Review recent changes: new vendors, DNS edits, list imports, volume spikes.
Likely causes#
- Never sunsetting because list size is a vanity metric.
- Using 'We miss you' subject lines that read as spam.
Fix and re-verify#
- Define inactivity: no clicks or replies in 90 days is a common threshold.
- Send a 2 to 3 message win-back series with a clear ask to stay subscribed.
- Suppress anyone who does not engage after the series.
- Keep a record of suppressed contacts for compliance and future opt-in.
Frequently asked questions#
Will sunsetting hurt my revenue?
Rarely. Inactive contacts produce little revenue, and improved placement for engaged contacts usually offsets any loss.