status=bounced (host gmail-smtp-in.l.google.com[142.250.125.27] said: 550-5.7.1 Our system has detected an unusual rate of unsolicited mail) Or in the header of a delivered email:
This report is structured for IT administrators, email marketers, and developers who need to understand why emails are blocked, how to diagnose the issue, and how to prevent it. 1. Executive Summary Gmail (Google Workspace & personal @gmail.com) blocks or filters over 10 billion emails per day —roughly 85% of all inbound traffic. “Blocked” does not always mean a hard rejection (bounce). It encompasses three distinct states: Hard Bounce (explicit block), Soft Bounce (temporary deferral), and Silent Drop (spam folder). blocked emails gmail
The sender used a new shared IP that previously sent crypto spam. Google’s IP reputation cache carried over. status=bounced (host gmail-smtp-in
increase(smtp_550_5_7_1_total[5m]) > 10 Scenario: A tech newsletter with 95% open rate suddenly gets blocked by Gmail. “Blocked” does not always mean a hard rejection (bounce)