What’s an acceptable complaint rate by provider?

Mailbox providers publish specific "rules of the sea," and the Gmail and Yahoo 2024 bulk sender requirements set the global standard. These providers set two critical, non-negotiable thresholds for all bulk senders:

The "Safe" Threshold: Senders are expected to keep their complaint rate below 0.10% (1 complaint per 1,000 messages) to be considered a trusted sender. The "Hard" Threshold: Senders must stay below 0.30% (3 complaints per 1,000 messages).

Providers measure this using data from tools like Google Postmaster Tools. Reaching the 0.30% hard limit is a severe violation and will trigger immediate penalties, including message deferrals and rejections. These are the maximums the harbor will tolerate before seizing your vessel.