Klaviyo Emails Going to Spam: Troubleshooting Guide

Most Klaviyo deliverability problems have the same root causes: sending to disengaged subscribers, authentication misconfiguration, or domain reputation damage. This guide walks through diagnosing and fixing the most common issues, starting with the data you need before changing anything. Klaviyo’s own deliverability documentation identifies list engagement quality as the single largest variable in inbox placement outcomes.

Klaviyo’s bands come from the deliverability tab documentation. Gmail’s figures come from Google’s sender guidelines and the guidelines FAQ. They are not interchangeable. Klaviyo also tells you Gmail does not feed spam complaints back to the ESP, so the Hub can look calm while Postmaster Tools does not. You can compute your own rate with the free spam complaint rate calculator.

Last verified: 26 September 2026.

If the spam placement was sudden

Compare the failing send with the last one that placed normally. On a Klaviyo store the change is usually one of these:

The general version of this diagnosis is why emails go to spam. Klaviyo-specific skips, where the customer never got a message because the platform held it, are delivered but not received. If opens or clicks look healthy while placement is poor, bot clicks in Klaviyo explains how Apple MPP and security scanners inflate them.

Diagnose Before You Fix

Before changing anything, gather data:

• Klaviyo’s Deliverability Hub: bounce rate, complaint rate, and the per-inbox-provider breakdown for the last 30 days. Read it against Klaviyo’s own bands. The Deliverability Hub guide explains what the Hub cannot show, including which folder the message landed in.
• Google Postmaster Tools: Compliance status and spam rate for the branded domain. Google has said the domain and IP reputation dashboards will be retired, with no date published and both still present, so do not wait on a High or Low badge.
• Yahoo: Yahoo’s bulk-sender requirement is a complaint rate under 0.30% on mail that reached the inbox, and Yahoo’s own Sender Hub is where it reports complaint feedback. InboxEagle does not connect to Sender Hub. It reads Yahoo and AOL seed mailboxes after each send to show whether mail landed in the inbox, promotions, or spam.
• Placement: InboxEagle seed mailboxes report inbox, spam, or promotions at Gmail, Yahoo, AOL and Outlook. That is the folder. Klaviyo’s delivered count is the acceptance.

The Most Common Klaviyo Deliverability Problems

1. High Spam Complaint Rate

Symptom: Klaviyo complaint rate above the 0.08% Klaviyo recommends, or a Google Postmaster Tools spam rate at or above Google’s 0.10% guideline (never let it reach 0.30%)

Root causes:

• Subscribers don’t remember signing up
• Sending too frequently
• Irrelevant content for the segment

Fixes:

• Add a sunset flow: auto-suppress subscribers who haven’t opened in 90 days
• Use preference centers so subscribers can choose their frequency
• Segment by purchase history and engagement before sending

2. Shared IP Warm-Up Issues

If you’re on Klaviyo’s shared IP pools and you’re new or had a long sending gap:

• Start with your most engaged segment (opened in last 30 days)
• Gradually increase volume over 4–6 weeks
• Monitor bounce rates and complaints daily during warm-up

3. Domain Reputation Degradation / Compliance Failures

Symptom: Postmaster v2 Compliance Dashboard shows authentication failures or elevated spam rate; complaint rate trending upward in Klaviyo’s Deliverability Hub

Google has said the domain and IP reputation dashboards will be retired. No retirement date is published, and both cards have remained visible, so treat a High or Low label as temporary. Compliance status and the spam-rate dashboard are the figures Google documents in the sender guidelines.

This is the most serious issue. Recovery is slower than a DNS change, and mailbox providers do not publish a week count. The Validity 2025 Benchmark Report describes multi-week engaged-only sending before placement returned for the senders in that report. Treat that as one research group’s observation, not a clock Gmail promised you.

Recovery plan:

1. Pause all non-essential campaigns
2. Only send to your highest-engagement segment (opened in 7 days)
3. Send high-value, highly relevant content
4. Monitor Postmaster compliance dashboard and spam rate daily
5. Gradually expand your sending audience once complaint rate is back below the 0.08% Klaviyo recommends

4. Microsoft Outlook Placement Issues

Since May 2025, Microsoft enforces bulk sender requirements for Outlook, Hotmail, and Live.com addresses. Klaviyo senders on shared IP pools should note:

• A non-compliant sender on a shared IP can affect Outlook placement for other senders on that pool
• Verify your SPF, DKIM, and DMARC are configured correctly. Klaviyo’s domain authentication handles DKIM, but SPF and DMARC must be set up at your domain registrar
• If you’re seeing Outlook-specific placement issues, start with the bounce log. Microsoft’s own SNDS (Smart Network Data Services) gives IP-level signals, but InboxEagle does not integrate with it

5. DKIM Not Configured Correctly

Klaviyo requires you to add CNAME records to your DNS for DKIM signing. Verify:

1. Go to Klaviyo → Settings → Email → Sending domains
2. Click “Verify DNS” to check all records
3. If any are red, update your DNS records

6. List Quality Issues

Signs: Bounce rate creeping above 2%, complaint rate elevated

Audit your list:

• Remove all hard bounces immediately (Klaviyo does this automatically)
• Suppress soft bounces after 3+ consecutive bounces
• Run a re-engagement campaign for cold subscribers

How to Improve Email Deliverability in Klaviyo

To improve email deliverability, Klaviyo senders should work in a fixed order, because each step depends on the one before it. In Klaviyo, improve deliverability first by fixing what the receiving server can verify (authentication), then what recipients feel (list quality and frequency), then what Klaviyo cannot show you (Gmail’s spam rate and real placement). A single “Delivered” number in Klaviyo measures acceptance, not placement.

1. Authenticate a branded sending domain. Follow the custom sending domain setup so DKIM signs under your brand and DMARC aligns. The Klaviyo authentication guide explains why the default setup falls short.
2. Send to engaged subscribers first. Put recently engaged profiles ahead of colder segments, especially after a long gap in sending.
3. Keep Smart Sending on for marketing sends, and leave it off only for transactional messages.
4. Read Gmail separately. Gmail does not return complaints to Klaviyo, so track the spam rate in Google Postmaster Tools.
5. Verify with a placement test after every change, not only the Deliverability tab.

How Do I Check If My Klaviyo Emails Are Landing in Spam?

Klaviyo’s “Delivered” status confirms the receiving server accepted the message. It does not say whether the message went to the inbox, Promotions or spam. To check whether your Klaviyo emails are landing in spam, combine three views: the Gmail spam rate in Postmaster Tools, a seed-list placement test that shows the folder at Gmail, Yahoo, AOL and Outlook, and the Authentication-Results header on a message that did land in spam. For a quick content check before a send, the free email spam tester needs no account.

Klaviyo-Specific Best Practices

Use Smart Sending

Klaviyo’s Smart Sending feature skips a second marketing email to the same recipient inside a window you set (16 hours by default). Enable it on campaigns and on marketing flows to protect engagement rates. Leave it off for transactional messages a customer is waiting on, such as order confirmations.

Leverage Predictive Analytics

Klaviyo’s predictive analytics show you each subscriber’s optimal send time and predicted CLV. Use this data to prioritize high-value segments.

Monitor Placement After Every Send

Set up Klaviyo’s deliverability dashboard alerts and supplement them with placement you can actually see. Postmaster Tools data arrives 24 to 48 hours late, so it confirms a problem rather than catching it live. The Klaviyo integration connects InboxEagle to the sends you already make. Seed list testing reports inbox, spam, or promotions at Gmail, Yahoo, AOL and Outlook. Microsoft authentication rejections (550 5.7.515) are SMTP-time bounces, so those still show in your bounce log.

The Bottom Line

Klaviyo deliverability problems are diagnosable and fixable, if you start with data rather than assumptions. The expensive mistake is changing several things at once and not knowing what worked.

• Check Postmaster Tools and Klaviyo’s Deliverability Hub first. Identify the provider and the metric that is failing before changing anything.
• Authentication is the floor. DKIM via Klaviyo sending domains, SPF and DMARC at your registrar. Passing them does not guarantee the inbox.
• Suppress people who have not engaged if complaints are the problem. A sunset flow is one way to do that. It does not, by itself, repair a Gmail spam rate that is already high.
• During recovery, mail recent clickers first. Volume is not the signal mailbox providers reward.
• Seed test before every major send. InboxEagle’s seed list shows inbox, spam, or promotions at Gmail, Yahoo, AOL and Outlook for that message.

Verify the fix

After you change the segment, the DNS, or the flow overlap, do not restore the original audience on the next send.

1. Send to subscribers who clicked recently.
2. On a received copy, confirm SPF, DKIM, and DMARC pass for the branded domain.
3. Check placement at Gmail, Yahoo, AOL and Outlook.
4. The next day, read Postmaster Tools spam rate. Klaviyo’s complaint number will not update that Gmail figure for you.
5. Expand the audience only if that smaller send placed in the inbox and the complaint band did not move into needs attention.

If authentication passes and recent clickers still land in spam, stop expanding and follow the recovery process. Mailbox providers do not publish a fixed number of weeks for reputation to return. Treat any multi-week plan as an operating pace, and judge it by spam rate and placement, not by a calendar.

Connect Klaviyo to InboxEagle

InboxEagle connects directly to Klaviyo to track campaign-level inbox placement, identify which campaigns are sending to spam, and see which domains are pulling down your overall reputation. See Klaviyo Integration to connect and Klaviyo Analytics for campaign performance tracking.

When to Contact Klaviyo Support

If you’ve done all the above and still have placement issues:

• Open a deliverability support ticket with specific data (send date, segment, complaint rates)
• Ask about dedicated IP options if you’re sending 100K+ emails/month
• Request a deliverability review for a fresh set of eyes