Check identity and sending habits
Confirm that the domain used in the visible From address is aligned with the authentication your mail provider expects. Review SPF, DKIM, and DMARC configuration with the provider's setup guidance, and avoid changing DNS records without understanding existing senders.
Sudden volume increases, inconsistent sending patterns, or a new domain with no history can look unusual. Ramp legitimate traffic gradually, separate transactional and promotional mail where appropriate, and stop sending to addresses that repeatedly bounce.
Make the message expected
Use a recognizable sender name and subject that match what the recipient signed up to receive. Explain the value and frequency of recurring messages, and provide a working unsubscribe or preference link that is easy to find.
Monitor delivery and complaint signals by provider and campaign rather than relying on a single overall rate. If placement changes abruptly, pause the affected stream and investigate authentication, list source, and recent content changes before resuming.