Spam complaint rate

Spam complaint rate is the share of delivered messages that recipients mark as spam, reported back through feedback loops and provider postmaster tools. It is the quickest way to lose inbox placement, because providers weight it heavily and react within days. Gmail asks bulk senders to stay under 0.3 per cent and treats 0.1 per cent as the working target. Apple offers no feedback loop, so the rate you can see understates the real one.