How to Fix Klaviyo Deliverability and Stop Landing in Spam

Diagnose Your Deliverability in the Klaviyo Dashboard

If your open rates are dropping, start by checking your deliverability metrics inside Klaviyo. Deliverability is measured across your entire sending domain. When mailbox providers like Gmail notice users marking your messages as spam or ignoring them entirely, they flag your domain for every other subscriber on that network.

You need to spot where you are falling short before changing random settings. Check your account deliverability tab for bounce rates, unsubscribe rates, and spam complaint rates. If your open rates have dipped below 30% or your click rates sit below 0.5%, your domain reputation is suffering.

For more detail, see How to reduce high email bounce rates in your Klaviyo account.

Add Critical Flow Filters to Protect Automated Sends

High bounce rates destroy sending reputation fast. In Klaviyo, a soft bounce is a temporary delivery failure, whereas a hard bounce is a permanent failure (such as an invalid address). If a profile logs five consecutive soft bounces, Klaviyo suppresses them automatically. You should not wait for that to happen inside your active automations.

Go into every core flow and add a strict flow filter at the trigger level: Person has bounced email zero times in the last 30 days. If an address bounces once, this filter immediately ejects them from the sequence for the next month. That single rule stops broken addresses from repeatedly damaging your sender score across multi-step sequences.

I also recommend adding an explicit consent filter to standard automated flows. Set the condition to verify that the person can receive email marketing because they explicitly subscribed. Filtering unconfirmed profiles out of high-volume flows protects your list health over time.

Switch to Double Opt-in if Inbound Quality Plummets

When bad deliverability stems from fake or mistyped emails entered into your pop-up forms, you need to tighten the front door. Head into your main subscriber list, open the list settings, and switch your consent method from single opt-in to double opt-in.

For more detail, see Why Your Emails Land in Promotions and How to Fix It.

Double opt-in requires every new subscriber to click a confirmation link in their inbox before they are added to your list. It will noticeably reduce your raw opt-in volume. That is the trade-off. However, it completely eliminates bot submissions, spam traps, and typo-ridden addresses while you rehabilitate a damaged domain.

Rebuild Campaign Health with Tiered Engaged Segments

Blasting campaigns to your entire database is the fastest way to land in spam. When an account comes to us with poor deliverability, our first move is always strict engagement segmentation. We build three distinct engagement windows: 30-day, 60-day, and 90-day engaged segments.

Your 30-day engaged segment should include anyone who can receive marketing and has opened an email, clicked an email, placed an order, or subscribed in the last 30 days. When deliverability is compromised, send campaigns exclusively to this 30-day group. Keep sending only to them until your campaign open rates consistently sit above 40%.

For more detail, see Fixing Broken Campaign Deliverability with Klaviyo Segments.

Once you see stable metrics above that 40% mark, you can expand your audience. Move your campaign sends to your 60-day engaged segment. If open rates hold strong, expand again to your 90-day engaged segment. That is how you safely warm your audience back up without triggering inbox spam filters.

Authenticate Your Sending Domain

Sending campaigns from a shared default Klaviyo routing domain makes your reputation vulnerable. You must configure a dedicated sending domain in your account settings. This links your brand domain directly to your sending infrastructure.

Setting up your dedicated domain requires adding DNS records (including DKIM and SPF records, which prove to inbox providers that Klaviyo is authorized to send emails on your behalf) inside your domain host. Mailbox providers expect proper authentication from real brands. Skipping this step is asking for inbox placement issues.

Final Thoughts

Fixing bad deliverability comes down to discipline. Cut out unengaged profiles, filter out recent bounces from your flows, authenticate your domain, and restrict campaign sends to recent openers until your numbers recover. It takes consistency, but mailbox providers will reward you with reliable inbox placement.

Need Help Fixing Your Account?

If your emails are missing the primary inbox and you want our team to audit your setup, flows, and list health, book a comprehensive In-box account audit today.