Check 15 / 16 LOW impact In the full checklist
Sunset unengaged 90 days — keep deliverability >98%
What this check is
Subscribers who never open drag down deliverability for everyone else, and mailbox providers judge the whole sending domain. Removing the unengaged improves the inbox placement of the engaged.
How to implement it
Define an engagement window, send a final re-permission message, and suppress or delete those who do not respond to it. Exclude recent customers from the cut so you do not remove people who simply have not bought recently.
How to verify it
Check the deliverability metrics before and after the suppression: the open and click rates should rise and the bounce and complaint rates should not.
All 197 checks, one Google Sheet
This page is the summary. The full checklist carries the priority, the impact score and the tool link for every check — all 197 of them, across 14 categories, as a Google Sheet and CSV with lifetime updates.
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