What are the main causes of reputation damage?

Reputation damage typically originates from several core causes:

High complaint rates when recipients frequently mark mail as spam. This is the fastest path to reputation destruction.

Spamtrap hits indicating you are sending to addresses that should not exist on any legitimate list. Pristine traps are particularly damaging.

Poor list hygiene with high bounce rates from invalid addresses, suggesting purchased lists or outdated data.

Authentication failures where SPF, DKIM, or DMARC consistently fail, preventing reputation from building in the first place.

Volume spikes that look like spam behavior when sending patterns suddenly change dramatically.

Sending to disengaged recipients who consistently ignore messages, triggering silent filtering.

Reputation damage is rarely a single event. It usually results from accumulated poor practices, like a ship's hull gradually deteriorating from neglected maintenance.