What are the consequences of non-compliance?
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So you've heard about Gmail and Yahoo's 2024 requirements, but you're wondering what actually happens if you ignore them. The short answer: things get worse fast, and they take a long time to fix.
The enforcement path follows a predictable escalation. First, you'll see more of your emails quietly landing in spam. Then you'll start hitting temporary delivery failures (those are 421 errors, meaning Gmail is deferring your mail while it watches you). If you still don't fix things, you hit 550 errors. That's a hard rejection. Your emails don't even arrive.
Yahoo Mail follows the same pattern: deferrals first, then blocking. The escalation isn't instant, but it's not forgiving either. Once you're in hard-rejection territory, you've got a real problem on your hands.
The part that stings most is the recovery timeline. A few weeks of non-compliance can take months of clean sending to undo. Reputation damage builds faster than it heals. (That asymmetry is why prevention is so much cheaper than remediation, in time, cost, and stress.)
What does "clean sending" even mean during recovery? It means hitting your spam complaint rate thresholds, having authentication in place, processing unsubscribes quickly, and sending only to people who actually want your emails. All of it, consistently, over weeks.
If you're not sure where you stand right now, the next step is to check. You can use our free SPF checker and DKIM checker to verify your authentication is set up correctly. If things are already going sideways, our SOS hotline is free and we actually pick up.
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