Your Klaviyo Emails Are Going to Spam. Here's How to Fix It.

You're building flows, writing campaigns, A/B testing subject lines — and none of it matters. Because your emails aren't reaching the inbox.

Here's the scary part: Klaviyo won't tell you this is happening. Your "delivered" rate might show 98%. But "delivered" doesn't mean "inbox." It means the receiving server accepted the email. It could be sitting in spam, the Promotions tab, or a black hole nobody checks.

The only way to know is to test. And when we test for our clients, the results are often ugly. We've audited Klaviyo accounts where 30-40% of emails were landing in spam at Gmail — the largest email provider on earth. That's not a minor issue. That's a revenue emergency.

We're Klaviyo Gold Partners at GOSH Digital. Deliverability is the first thing we fix in every account we touch. Here's exactly how to diagnose and fix yours.

How to Check If You Have a Deliverability Problem

Before we fix anything, let's figure out where you actually stand.

Method 1: Check Your Klaviyo Metrics

Go to Analytics > Metrics in Klaviyo. Pull up your campaign data for the last 90 days. Look at these numbers:

| Metric | Healthy | Warning | Emergency | |---|---|---|---| | Open Rate | 25%+ | 15-25% | Under 15% | | Click Rate | 2.5%+ | 1-2.5% | Under 1% | | Bounce Rate | Under 2% | 2-5% | Over 5% | | Spam Complaint Rate | Under 0.01% | 0.01-0.05% | Over 0.05% | | Unsubscribe Rate | Under 0.3% | 0.3-0.5% | Over 0.5% |

If your open rates have been declining steadily over the last 3-6 months, that's the biggest red flag. It usually means inbox providers are quietly routing more of your emails to spam.

Method 2: GlockApps (The Real Test)

GlockApps is an inbox placement tool that actually sends test emails to seed addresses at Gmail, Yahoo, Outlook, and others, then tells you where they landed: inbox, spam, promotions, or missing.

How to use it:

1. Sign up at glockapps.com (they have a free trial)
2. Create a test
3. Copy the seed email addresses they give you
4. In Klaviyo, create a test campaign and send to the seed list
5. Wait 15 minutes, then check GlockApps for results

What to look for: If more than 10% of your test emails land in spam at any major provider, you have a deliverability problem that needs immediate attention.

We run GlockApps tests monthly for every client. It's non-negotiable.

Method 3: Google Postmaster Tools

If you send to a lot of Gmail addresses (most brands do — Gmail is 30-40% of most email lists), set up Google Postmaster Tools. It's free.

1. Go to postmaster.google.com
2. Add and verify your sending domain
3. Wait 24-48 hours for data to populate

Google Postmaster shows you your domain reputation (High, Medium, Low, Bad), spam rate, authentication pass rates, and encryption status. If your domain reputation is anything below "High," you have work to do.

Step 1: Set Up a Dedicated Sending Domain

This is the single most impactful deliverability fix for most Klaviyo accounts.

By default, Klaviyo sends emails from a shared sending domain and IP. That means your sender reputation is partially determined by other Klaviyo users on the same infrastructure. If they're doing sketchy stuff, your deliverability suffers.

The fix: dedicated sending domain.

In Klaviyo, go to Settings > Email > Sending Domain. Click "Get Started" under the dedicated sending domain section. Klaviyo will give you DNS records to add to your domain provider (GoDaddy, Cloudflare, Namecheap, etc.):

• DKIM records: Two CNAME records for email authentication
• SPF record: A TXT record authorizing Klaviyo to send on your behalf
• DMARC record: A TXT record telling inbox providers what to do with unauthenticated emails from your domain

The DNS records look like this:

| Type | Host/Name | Value | |---|---|---| | CNAME | k1._domainkey.yourdomain.com | dkim.klaviyo.com | | CNAME | k2._domainkey.yourdomain.com | dkim2.klaviyo.com | | TXT | yourdomain.com | v=spf1 include:_spf.klaviyo.com ~all | | TXT | _dmarc.yourdomain.com | v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com |

Important: If you already have SPF or DMARC records, don't create new ones. You can only have one SPF and one DMARC record per domain. Add the Klaviyo include to your existing SPF record.

After adding the records, go back to Klaviyo and click "Verify." It can take up to 48 hours for DNS to propagate, but usually it's done within a few hours.

Why this matters: A dedicated sending domain means your reputation is 100% based on YOUR sending behavior. Nobody else's bad practices can drag you down. We've seen open rates increase 5-15% within 30 days of switching to a dedicated sending domain.

Step 2: Warm Up Your Sending Domain (Don't Skip This)

If you just set up a dedicated sending domain — or if you're starting a brand new Klaviyo account — you need to warm up.

Warming up means gradually increasing your send volume so inbox providers learn that your domain sends legitimate email. Send too much too fast, and they'll treat you like a spammer.

The warm-up schedule we follow:

| Week | Daily Volume | Who to Send To | |---|---|---| | Week 1 | 500-1,000 | Most engaged subscribers only (opened in last 30 days) | | Week 2 | 2,000-5,000 | Engaged subscribers (opened in last 60 days) | | Week 3 | 5,000-10,000 | Engaged subscribers (opened in last 90 days) | | Week 4 | 10,000-25,000 | Engaged + recently active subscribers | | Week 5+ | Full volume | Full engaged list (NOT unengaged) |

Rules during warm-up:

• Send to your MOST engaged subscribers first. This generates high open rates, which tells inbox providers your email is wanted.
• Don't send to anyone who hasn't opened an email in 90+ days during warm-up. Their non-engagement will tank your reputation before it's established.
• Keep your content clean. No heavy images, no spammy subject lines, no all-caps. Inbox providers are extra suspicious of new sending domains.
• Monitor GlockApps weekly during warm-up to catch issues early.

How long does warm-up take? 4-6 weeks for most brands. Larger lists (100K+) may need 8 weeks.

Can I skip warm-up? No. We've seen brands skip warm-up and end up in spam at Gmail for months. It's much harder to recover from a bad reputation than to build a good one from scratch.

Step 3: Clean Your List (Ruthlessly)

Your email list is not an asset if half of it is dead weight. Unengaged subscribers actively hurt your deliverability because they signal to inbox providers that people don't want your email.

The list hygiene protocol we run quarterly:

Remove Hard Bounces

Go to Profiles in Klaviyo. Filter by "Suppressed > Bounced." These are email addresses that don't exist (hard bounce) or whose mailbox is full (soft bounce converted to hard). Klaviyo automatically suppresses hard bounces, but review the list to make sure.

Suppress 180-Day Unengaged

Create a segment:

Has NOT opened email in last 180 days
AND has NOT clicked email in last 180 days
AND has NOT placed order in last 180 days

Anyone in this segment should be suppressed. They're not coming back, and they're hurting everyone else's inbox placement.

"But that's 40% of my list!" — Yes, and they're dead subscribers. A list of 10,000 engaged subscribers outperforms a list of 50,000 where 40K are ghosts. Every time.

Run an Email Verification Service

Use a tool like ZeroBounce, NeverBounce, or BriteVerify to verify your remaining list. They identify:

• Invalid email addresses
• Catch-all domains (accept everything, deliver nothing)
• Spam traps (addresses specifically designed to catch senders with bad practices)
• Role-based emails (info@, admin@, sales@ — these never engage)

Cost: $0.003-$0.01 per email verified. For a 50K list, that's $150-$500. Worth it.

How to do it: Export your Klaviyo list as CSV, upload to the verification service, download the results, then suppress the invalid/risky addresses in Klaviyo.

Step 4: Build a Sunset Flow

A sunset flow is an automated sequence that identifies unengaged subscribers, gives them one last chance to re-engage, and suppresses them if they don't. It's your ongoing list hygiene engine.

The sunset flow structure:

Trigger: Segment — "Has not opened or clicked in 60 days AND has not purchased in 60 days"

Email 1 (Day 0): "We miss you — are you still interested?"

• Plain text or minimal design
• Ask them to click a link or button to confirm they want to keep receiving emails
• Subject: "Should we stop emailing you?" (This subject line gets 30%+ open rates because curiosity is powerful)

Email 2 (Day 5): "Last chance to stay on our list"

• Same ask — click to confirm
• Add a small incentive: "Click here to stay + get 15% off your next order"

After Email 2: Wait 7 days. Anyone who didn't open or click either email gets automatically suppressed.

Result: Your list continuously cleans itself. We've seen this improve overall deliverability by 10-20% within 60 days.

Step 5: Fix Your Campaign Sending Practices

Even with perfect technical setup, bad sending practices will tank your deliverability.

Send Consistently

Don't go from 0 emails per week to 5 emails during a sale. Inbox providers notice volume spikes and flag them. If you normally send 2 campaigns per week, ramp up to 3 the week before a sale, then 4-5 during the sale. Gradual increases.

Send to Engaged Segments

I said this in the segmentation guide and I'll say it again: stop sending to your full list. Every campaign should go to Engaged 30-Day or Engaged 90-Day segments. The only exception is major events (BFCM, huge sale) where you extend to 90-day or 120-day engaged.

Watch Your Spam Complaint Rate

If your spam complaint rate per campaign exceeds 0.05%, something is wrong. Common causes:

• Sending too frequently (people forget they signed up)
• Sending to unengaged subscribers (they mark as spam instead of unsubscribing)
• Misleading subject lines (the email doesn't deliver what the subject promised)

Gmail has said publicly that a spam complaint rate above 0.1% will result in deliverability penalties. Stay well below that.

Authenticate Everything

Make sure DKIM, SPF, and DMARC are all passing. In Klaviyo, go to Settings > Email > Sending Domain and verify all three show green checkmarks. If any show errors, fix the DNS records immediately.

Step 6: Monitor Ongoing

Deliverability isn't a one-time fix. It requires ongoing monitoring.

Monthly checklist:

• [ ] Run a GlockApps inbox placement test
• [ ] Check Google Postmaster Tools domain reputation
• [ ] Review Klaviyo bounce rate (should be under 2%)
• [ ] Review spam complaint rate (should be under 0.01%)
• [ ] Check open rate trends (declining = problem brewing)
• [ ] Run the sunset flow and suppress non-engagers
• [ ] Verify DNS records are still correctly configured (occasionally they get overwritten during website changes)

Quarterly:

• [ ] Run email verification on your full list
• [ ] Review and update segment thresholds
• [ ] Audit all active flows for deliverability best practices

The Gmail Promotions Tab Problem

Let's talk about the elephant in the room. Even if you're not in spam, a huge percentage of your emails are landing in Gmail's Promotions tab. And while the Promotions tab isn't spam, engagement rates are significantly lower there.

Things that push you to Promotions:

• Heavy HTML with lots of images
• Marketing language ("Sale!", "Discount!", "Limited time!")
• Multiple links and CTAs
• Tracking pixels (Klaviyo adds these by default)
• Logos and branded headers

Things that push you toward Primary:

• Plain text or minimal HTML
• Conversational language
• Single link
• No images
• Looks like a personal email from a real person

Our approach: We don't try to avoid the Promotions tab for every email. Marketing emails belong there. But for specific high-priority sends — like VIP campaigns, founder messages, or win-back emails — we'll use a plain-text format that's more likely to land in Primary.

The plain-text hack: Create a Klaviyo template with no images, no logo, minimal HTML (just paragraph text and one link), and send from a personal-sounding sender name ("Mark from [Brand]" instead of "[Brand]"). These emails consistently land in Primary at Gmail and get 2-3x higher open rates than branded templates.

What Deliverability Costs You (Real Math)

Let's quantify this. Say you have a 50,000-subscriber list and you're sending 2 campaigns per week.

With 20% of emails going to spam (common for accounts with no deliverability work):

• Effective reach per campaign: 40,000 instead of 50,000
• Lost opens per campaign: ~3,000 (at 30% open rate on the missing 10K)
• Lost clicks per campaign: ~300 (at 3% CTR)
• Lost revenue per campaign: ~$1,500 (at $5 RPR)
• Lost revenue per month: $12,000
• Lost revenue per year: $144,000

That's not a rounding error. That's a senior employee's salary. And it's completely fixable.

The Recovery Timeline

If your deliverability is currently damaged, here's what the recovery looks like:

• Week 1-2: Implement dedicated sending domain, fix DNS records, suppress unengaged subscribers
• Week 3-4: Begin warm-up, send to most engaged only, monitor GlockApps
• Week 5-8: Gradually expand to full engaged list, launch sunset flow
• Week 8-12: Full recovery typically achieved, consistent inbox placement at Gmail, Yahoo, Outlook

It takes 2-3 months to fully recover from a damaged sender reputation. The sooner you start, the sooner you stop losing revenue.

Let Us Fix This for You

Deliverability is technical, tedious, and absolutely critical. If your Klaviyo emails are underperforming and you suspect inbox placement is the issue, we'll diagnose it for free.

Our audit includes a GlockApps placement test, DNS authentication review, list health analysis, and a prioritized fix plan with expected revenue impact.

Book your free Klaviyo deliverability audit.

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Mark Cijo is the founder of GOSH Digital, a Klaviyo Gold Partner agency that's driven $23M+ in revenue for 150+ eCommerce brands. He's personally fixed deliverability for accounts that were 40% in spam — and watched the revenue come back.