Spam complaint rate in practice
This is the metric mailbox providers weigh most, because it is a direct human verdict on your email. Google's email sender guidelines ask all senders to keep the user reported spam rate in Postmaster Tools below 0.10% and to avoid ever reaching 0.30%. Yahoo publishes a similar threshold.
Complaints usually come from relevance, not wording. Someone who has no reason to hear from you reaches for the spam button because it is easier than replying. Sending fewer emails to accounts with a real signal is the most reliable way to keep complaints down, and an easy opt out gives people a better option than the spam button.
Google: Email sender guidelines
Last updated 2026-10-14 by Ishan Vats.
