Every send is a vote on your reputation. Mailing addresses that never existed, never opted in, or have not engaged in a year is how good domains end up on blocklists.
Remove these first
- Hard bounces and known invalid syntax.
- Role accounts (info@, sales@) unless you have a documented B2B reason and permission.
- Complaints and legal suppression, immediately.
- Unengaged subscribers past your cutoff — often 90 to 180 days depending on frequency.
Confirm before you blast
Double opt-in is still the cheapest insurance for consumer lists. For imported B2B lists, require a paper trail: who captured the address, when, and for what. Purchased lists are not a gray area; they are how you inherit spam traps.
Sunset instead of sudden silence
A short win-back sequence with an obvious preference center is fair. If they still do not engage, stop. Continuing to mail them to “keep the list large” is how complaint rates climb while revenue per send falls.
