Email Deliverability Guide
Google's threshold is a tight spam-rate threshold. Above that, they start throttling your emails. Here's how to fix it.
Since February 2024, Gmail enforces a hard spam complaint threshold for bulk senders. Exceed it and your emails start getting throttled, fewer land in the inbox, more go to spam, and your sender reputation tanks. Yahoo follows similar rules. This isn't optional. This is the new reality of email marketing.
Most eCommerce brands have no idea what their spam rate is until deliverability crashes. They keep blasting their full list, spam complaints accumulate silently, and one day their open rates drop from a weak baseline with no apparent cause. By then, recovery takes months.
This is the playbook we use when spam rate is the problem. The playbook below is what we do every time. Follow it exactly, skipping steps makes recovery take twice as long.
150+
Clients
$70M+
Revenue
$23M+
Ad Spend
Klaviyo Gold Partner
Klaviyo Gold Partner
How to fix this, step by step
Check your actual spam rate in Google Postmaster Tools
Go to postmaster.google.com and register your sending domain. It takes 24-48 hours to show data. Look at your Spam Rate tab: green means safe, yellow means warning, red means critical (critical). If you haven't set this up yet, do it immediately. You cannot fix what you cannot see. This is the single most important diagnostic tool for email deliverability.
Stop all sends to unengaged subscribers immediately
If your spam rate is strong, stop sending to anyone who hasn't opened or clicked in the last 30 days. Yes, this will dramatically reduce your send volume. That's the point. Unengaged subscribers are the ones reporting you as spam, because they forgot they subscribed, don't want your emails, or Gmail is putting your emails in a place where marking spam is easier than finding unsubscribe. Shrink to your engaged audience and rebuild from there.
Verify your authentication records are perfect
SPF, DKIM, and DMARC must all be properly configured. In Klaviyo, go to Settings → Domains and check for green checkmarks. If anything is red or yellow, fix the DNS records immediately. Gmail and Yahoo require proper authentication for all bulk senders. Missing DMARC alone can push your emails toward spam. Use dmarcanalyzer.com or mxtoolbox.com to verify your setup.
Make unsubscribe stupidly easy to find
Counterintuitive but critical: making it easy to unsubscribe reduces spam complaints. A customer who can't find the unsubscribe link hits the "Report Spam" button instead. Spam complaints are much more damaging than unsubscribes. Put a visible unsubscribe link at the top of your email (not just the footer). Gmail now requires one-click unsubscribe in email headers, make sure Klaviyo's List-Unsubscribe header is enabled.
Run a re-permission campaign for borderline subscribers
For subscribers who last engaged 30-90 days ago, send a re-permission email: "We want to make sure you still want to hear from us. Click here to stay subscribed." Anyone who doesn't click once the work is in market gets suppressed. This proactively removes people who would otherwise become spam reporters. You'll lose quiet contacts from this segment, and that's exactly the dead weight that was dragging your reputation down.
Warm your sending volume back up slowly
After cleaning your list, don't jump back to your old send volume. Week 1: send to your 15-day engaged segment only. Week 2: expand to 30-day engaged. Week 3: expand to 60-day engaged. Monitor spam rate in Postmaster Tools after each expansion. If it stays too low, you're recovering. If it spikes, pause and re-clean. Full recovery takes focused disciplined sending.
Want us to handle this?
This playbook will stop the bleeding and start the recovery. If you follow every step without shortcuts, your spam rate will drop too low once the work is in market.
But maintaining healthy deliverability requires ongoing vigilance: list hygiene, engagement monitoring, authentication management, and content optimization. That's part of what we do for every Klaviyo client. If you want a full deliverability report and recovery plan specific to your account, we'll do it for free.
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