A company noticed open rates fall off a cliff with no change to their content. The cause was invisible to them but obvious in the data: their mail had quietly started landing in spam.
Diagnosing the drop
Investigation revealed missing authentication, a damaged sending reputation, and a list bloated with dead addresses — a combination that mailbox providers treat as a red flag.
The recovery plan
- Implement SPF, DKIM and DMARC correctly across the domain.
- Migrate to a clean, monitored sending setup.
- Prune the list and rebuild engagement gradually.
Back in the inbox
Within weeks, reputation recovered and engagement returned. The lasting win was the monitoring that now catches any future slip before it becomes another silent outage.