What is the spam complaint rate threshold?

The spam complaint rate threshold sets maximum acceptable complaints at 0.3% with a recommended target below 0.1%. Exceeding 0.3% triggers increased filtering, potential blocking, and reputation damage that takes time to repair.

Complaint rate is calculated as spam reports divided by delivered messages. Gmail measures this through their internal systems while Yahoo uses feedback loop reports. Both providers monitor these rates continuously and respond to threshold violations.

Maintaining low complaint rates requires sending relevant content to engaged subscribers, honoring unsubscribe requests promptly, and managing list quality actively. Recipients who do not remember subscribing or no longer want your mail generate complaints that damage your standing.