By Russell CargillIn a nutshell
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👀 Start with the symptom you can see
Write down what might be going on next to those symptoms.
Then check each one in the account before you decide what to fix.
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🔐 Keep authentication and complaint rate on the list
Put this on the list of possible root causes, then check it in the account.
Gmail's sender guidelines ask bulk senders for SPF + DKIM + DMARC (the records that prove the email comes from you).
They also ask for a From address that matches the domain you authenticated, and one-click unsubscribe on marketing mail.
Keep the spam complaint rate under 0.3% if you send at bulk volume. Aim under 0.1%.
In Postmaster, read Compliance Status, spam rate, authentication, and delivery errors. The older High / Medium / Low reputation labels retired around September 2025.
Yahoo asks for the same authentication, one-click unsubscribe, and complaint-rate baseline. Outlook now wants SPF, DKIM, and DMARC on high-volume senders too.
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💰 When you read the reports, use clicks, orders, and revenue per recipient
Bounce rate and complaint rate tell you whether mail can still reach the inbox.
Treat opens as a backup number. Apple Mail Privacy Protection prefetches opens, so that number can look better than the list is. When the reports are open, read clicks and orders before you lean on opens.
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🛒 Keep flow reach on the list of possible root causes
A flow can look finished in Klaviyo and still miss most of the people it was built for.
Compare entered with received before you rewrite the email. That check tells you whether reach belongs with the causes you test next.
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💊 When you confirm several causes, start with treatment priority
When you confirm several causes, start with treatment priority. On this account that was tracking so flows could send, authentication so mail could land, then people who never open.
For each treatment in the treatment plan, pick one number to check after the change.
What you are auditing in 2026
A Klaviyo audit in 2026 still walks seven parts of the account: account setup, deliverability, list health, flows, campaigns, forms, and tracking. Write the symptoms first, then keep a list of possible root causes next to those parts, so each section has a job.
Walking every section as a checklist still leaves you with a pile of notes. The list of possible root causes is what tells you which note explains the revenue you're worried about.
What to look at in Klaviyo
Profile fields, integrations, sending domain, and who can publish.
A missed branded domain here shows up later as an inbox problem.
Bounce, complaint rate, authentication alignment, and Postmaster Compliance status.
This is how you see whether Gmail is still happy to deliver mail from that domain.
How people joined, how many haven't opened in 90 days, and whether those people still get every campaign.
Welcome, cart, checkout, and post-purchase.
Compare people who entered with people who received email 1.
Who gets the send, how often, and revenue per recipient.
If you're emailing the whole list, look at that here, next to list health.
Where new people join, what they signed up for, and whether a giveaway or popup brought in people who never wanted the emails.
Viewed Product, Added to Cart, Started Checkout, Placed Order.
A live flow still misses people if these events never arrive, or if they enter and get skipped.
Authentication, event tracking, and who still gets campaigns belong on the list of possible root causes for most accounts. Write that list first, then check these against the account. Subject lines and send times stay on the list until those checks finish...
Three items that usually belong on the list
If your domain sends around 5,000 or more emails a day to personal Gmail inboxes, Gmail treats you as a bulk sender.
You need SPF and DKIM passing, a DMARC record (at least monitoring, written as p=none), a From domain that aligns with the authenticated domain, one-click unsubscribe on marketing mail, and a Gmail spam rate under 0.3% (aim under 0.1%).
Yahoo Sender Hub asks for the same authentication, one-click unsubscribe, and complaint-rate baseline. Outlook now wants SPF, DKIM, and DMARC on high-volume senders too.
Welcome, cart, and checkout flows only start if Shopify events arrive in Klaviyo (Viewed Product, Added to Cart, Started Checkout, Placed Order).
Count Started Checkout in Shopify and in Klaviyo for the same month.
People can also enter the flow and still get skipped. Filters and Smart Sending show up there.
People who haven't opened in 90 days, still sitting in every campaign, are more likely to hit spam or ignore the mail. That raises complaint risk.
A sunset rule - pausing people who stay quiet - belongs on the list of possible root causes, then you check whether those profiles still get every campaign.
You can check this in Klaviyo Settings → Domains, Klaviyo's Deliverability hub, and Google Postmaster Tools.
Klaviyo's hub will not show Gmail complaints the same way Postmaster does, because Gmail does not pass those complaints back to Klaviyo. In Postmaster, read spam rate, authentication, delivery errors, and Compliance status. The older High / Medium / Low reputation labels are gone.
Klaviyo already adds List-Unsubscribe and List-Unsubscribe-Post on marketing mail, so the unsubscribe header is usually present. Alignment still depends on a branded sending domain (the setup that lets SPF and DKIM match the From address). DMARC lives on the From / organization domain.
If the thing you're seeing is mail in spam or Promotions, why Klaviyo emails go to spam walks those inbox checks in the same order.
Pro tip: If you only have an hour this week, write the symptoms and the list of possible root causes first. Then use that hour on Settings → Domains, Postmaster Compliance status, and one flow: how many people entered vs how many got email 1. Those three checks tell you which items on the list are worth testing next...
Those seven areas plus the list of possible root causes are the map. Here's the same order on one account...
The list grew, email revenue did not
Read this in order. Each step leads into the next, and the numbers sit with the cause they belong to...
Step 1 - Symptoms
The list grew. Email revenue did not. That's what we started with.
Your dashboard might look like this too: more people on the list, less money from email, and a few tests already behind you. This team had hired a copywriter and tried new send times. Opens went up a little, then they went back down. They sent three campaigns a week to the full list. A giveaway about six months earlier had added around 12,000 people. Flows had not been reviewed in a long time.
Keep all of that with the numbers. It's background for the list of possible root causes, not an answer yet...
6 months ago
When we first looked
Also worth noting
- Opens moved from 24% to 16.2%
- 41% of profiles had been quiet for 90 days and still sat on every campaign
- They sent 3 campaigns a week to the full list
These are possible explanations, written before we pulled the reports. None of them are confirmed yet.
Six possible root causes
Step 2 - Possible root causes
Revenue down 20% over six months can come from a few places at once: deliverability, weaker list quality after the giveaway, a checkout flow that was missing people, full-list sending, three campaigns a week, tracking that stopped sending events, subject lines, inbox competition, seasonality, or an offer that trained people to wait.
Open rate went down slowly, week by week. That can happen when people who never open pile up, Gmail starts treating the domain more harshly, or the same templates keep going out. It can also be one break in tracking or authentication. We left both on the list until we checked. The board above is that list. Use the toggle if you want to see the same six items after the tests...
Step 3 - Evidence
We opened three tools and put what we found next to the list of possible root causes. Klaviyo for the list and the sends. Shopify for whether checkout events matched. Analytics for what email traffic did on the site.
Open rate had moved from 24% to 16.2%.
Click rate moved from 2.4% to 1.1%.
Revenue per recipient moved from $0.07 to $0.03.
41% of profiles had zero engagement in 90 days and still received every campaign.
There was no branded sending domain, so DKIM signed as Klaviyo's shared domain and did not align with the From address.
Campaigns went to the full list.
From Shopify, there were 2,040 checkout starts a month and 1,260 completions.
That is 38% abandonment - 780 people leaving checkout.
From Klaviyo events in the same month, there were 1,180 Started Checkout events.
About 860 Shopify checkouts never appeared in Klaviyo.
Email traffic was slightly up, while conversion from that traffic had moved from 2.1% to 0.9%.
Analytics credited $11,000 a month to email.
Klaviyo showed $14,400.
Different tools count email revenue on different rules, so that difference stayed on the list as "needs a shared definition," waiting on more evidence.
Three items had strong evidence: list quality after the giveaway, authentication alignment, and checkout reach, which was a mix of tracking and skips.
Frequency had some evidence behind it.
Subject lines and send times had already been tested.
Step 4 - Tests
Each test is paired with the cause it was checking, so you can see what checked out and what only had partial evidence...
In the list report, 41% of profiles were inactive.
Giveaway subscribers engaged about a third as much as people who found the brand on their own.
The list had grown, but the quality of that growth had slipped.
On authentication, there was no branded sending domain.
The branded sending domain's return-path CNAME (the record Klaviyo uses for SPF) was there, and it was set incorrectly. That is the SPF record to fix, not a random include on the root domain.
DKIM signed on Klaviyo's shared sending domain, so it failed alignment with the From address.
DMARC sat on monitoring only.
Google Postmaster Compliance status needed work, so spam rate became the number we kept an eye on after that.
On the checkout flow, Shopify showed 780 abandoned checkouts a month.
Klaviyo delivered the first email to 240 of those people (31%).
Of the 240 who received it, 48 clicked.
Revenue per recipient on the emails that arrived was $3.03.
When the email showed up, people clicked and bought. So most people who left checkout never got email 1. The problem there was reach.
Checkout reach
Shopify abandonment that month
540 of 780
Two things caused that 69% miss. Started Checkout events that never landed in Klaviyo, so those people never entered the flow. And Smart Sending on this checkout email, which skipped people who had just received a campaign. People who already bought should be skipped. That part is normal.
Copy and offer only apply to the 240 people who received email 1.
31% of abandoners
Revenue per recipient on the 240 who got it · 48 clicks
Same month · checkout events
People who already bought should be skipped in an abandonment flow. That filter is doing its job. The rest of the miss came from tracking plus Smart Sending left on this checkout email, which is why reach stayed on the treatment list.
Step 5 - Confirmed root causes
After the tests, three causes had enough evidence to treat. Frequency had some support. Two items stayed on the board without a treatment this round. The table below is the same board, written so you can scan it.
| Cause | Status | What confirmed it |
|---|---|---|
| List quality after the giveaway | Confirmed | 41% inactive; giveaway cohort far less engaged |
| Deliverability (no branded domain, weak SPF, DKIM out of alignment) | Confirmed | DNS records plus Postmaster Compliance status |
| Checkout flow reach loss | Confirmed | 69% of abandoners never received email 1; strong results when delivered |
| Frequency too high for this list | Supported | 3x weekly full-list sends to a quiet majority |
| Analytics vs Klaviyo revenue mismatch | Needs definition | $3,400 / month difference; different attribution windows |
| Subject lines and send times | Parked | Already tested; opens went up briefly, then they went back down |
Left on the board
- Subject lines and send times: Already tested. Opens moved up for a short stretch, then they settled back. We parked this until reach and authentication had a clean month.
- Analytics vs Klaviyo revenue: $11,000 in Analytics against $14,400 in Klaviyo. Different tools count email on different windows. We wrote down both numbers and used Klaviyo for treatment decisions until the brand picked one shared definition.
Step 6 - Treatment
When you confirm several causes, start with the base work. On this account that meant tracking so the flow could send, authentication so mail could land, then people who never open. Subject lines and send times stayed on the list until the tests finished. In this account they were parked...
Treatment order on this account
Turn on Klaviyo onsite tracking in Shopify, loosen the re-entry window to match how this brand's customers buy, and stop Smart Sending from blocking this flow.
The goal was to move first-email reach from 31% of abandoners toward 80%+.
Add a branded sending domain so DKIM aligns with the From address. Fix the return-path CNAME Klaviyo uses for SPF. Keep DMARC on monitoring (p=none), then tighten the policy after a clean month. Those bounce and reach numbers below are the numbers we watched on this account, not a published Gmail rule.
The goal was bounce rate from 3.8% to under 2%.
One winback email to 90-day inactives, then suppress anyone still quiet.
The goal was inactive share from 41% toward 30% or lower.
Results after 60 days
The three fixes took two weeks. Here's what moved on the same account...
60 days later
The rest of the numbers
| Metric | Before | After | |
|---|---|---|---|
| 💰 Email revenue / mo | $14,400 | $19,872 | +38% |
| 🛒 Checkout reach | 31% | 84% | +171% |
| 💵 Revenue per recipient | $0.03 | $0.07 | +133% |
| 👀 Open rate | 16.2% | 24.5% | +51% |
| 🖱️ Click rate | 1.1% | 2.8% | +155% |
| 🛍️ Conversion rate | 0.4% | 0.9% | +125% |
| 📉 Bounce rate | 3.8% | 1.2% | -68% |
| 🌙 Inactive share | 41% | 28% | -32% |
They'd spent six months on copy and timing. Confirming the causes took two weeks. The checkout fix showed up in the first month.
On this account, we would have missed the From-domain issue and the checkout reach issue if those hadn't stayed on the list of possible root causes until we tested them. The checkout emails that arrived already made money. Those three treatments together added $5,472 more a month.
A working pass you can run this week
Use the same order you just saw in the case. Write symptoms and possible root causes first, then open the matching reports, mark each cause, and build treatment priority from what the account confirmed.
What to look up this week
What changed in the last 6 months - a giveaway, an ESP move, a new offer, a new send cadence - and what has already been tried.
Open Settings → Account → Activity Log when the symptom has a start date. Filter by timeframe and look for domain, flow, or integration edits in that window.
Write the symptoms you can see, then the list of possible root causes on one page.
Do this before you pull the reports.
Pull a 90-day trend for clicks, placed orders, revenue per recipient, bounce, unsubscribe, and spam complaint.
Write down Klaviyo's attribution window (often 5 days on email) next to the Analytics number, so "email revenue" has one definition before you treat it as the money figure.
Compare campaigns against flows. Put what you find next to the list of possible root causes.
Open Settings → Domains and Google Postmaster Tools.
Read branded sending domain, SPF, DKIM alignment, DMARC, Gmail spam rate, and Compliance status.
Measure the share of profiles with zero engagement in 90 days, and whether those profiles still sit in campaign segments.
For welcome, abandoned checkout, and post-purchase, compare people who entered with people who received email 1.
If received is far below entered, keep reach on the list next to content.
Check that Started Checkout and Placed Order still land in Klaviyo, and whether Klaviyo's event count sits close to Shopify's.
Mark each possible root cause with the evidence you have.
Treat the confirmed causes first. Start that treatment plan from the treatment priority list.
Weekly pass in plain order
- Write what changed, and check the Activity Log if the symptom has a start date.
- Write the symptoms you can see, then the list of possible root causes on one page.
- Open Klaviyo analytics for 90 days, and write down how email revenue is counted.
- Open Settings → Domains and Google Postmaster Tools. Read Compliance Status, spam rate, authentication, and delivery errors.
- Measure quiet profiles and flow reach (entered vs received email 1).
- Mark each possible root cause, then build treatment priority from what the account confirmed.
If welcome is the flow that feels off, why the Klaviyo welcome flow is not converting walks signup to first order. If mail looks like it's landing in spam, why Klaviyo emails go to spam walks the inbox side. Add UTM tags on campaign and flow links so you can count revenue.
That answers how to audit Klaviyo in 2026. Start with the symptoms, keep a list of possible root causes, test each one against the account, then treat the confirmed root causes. Start that treatment plan with the base work.
That same order is the pass we run on an Email DDx account when you want the chart built for you.
Pro tip: Write the possible root causes on one page before you pull the reports. The list is easier to trust if you write it before you look at the numbers...
FAQ
How do you audit Klaviyo in 2026?
Start with the symptoms you can see, keep a list of possible root causes, test each one against the account, and then treat the confirmed root causes. Start that treatment plan with the base work.
Authentication, complaint rate, tracking, and whether flows reach people belong on the list of possible root causes, next to list, flows, and campaigns.
How often should you audit a Klaviyo account?
A full review every six months works well for most accounts, with a lighter check every quarter.
A monthly glance at clicks, revenue per recipient, bounce, and complaints is enough to catch trouble early.
How long does a Klaviyo audit take?
A careful do-it-yourself review on a small or mid-sized account is 4 to 8 hours, spread over two or three weeks, so you have time between checks for the numbers to settle.
Can I audit Klaviyo myself?
Yes. You need Klaviyo, your store, Google Analytics or the equivalent, and a spreadsheet. Google Postmaster Tools is free and worth the setup. A placement tool helps if you're not sure mail is reaching the inbox.
Which number should I trust first in a Klaviyo audit?
Revenue per recipient and placed-order rate for money. Click rate for whether people cared. Bounce and spam complaint for whether mail can land. Treat open rate as a backup number.
When Klaviyo and Analytics disagree, write both down and name the attribution window on each. Klaviyo often uses a 5-day email window. Pick one shared definition before you treat "email revenue" as the money figure.
What should I look at in Google Postmaster Tools in 2026?
Read Compliance Status, spam rate, authentication, and delivery errors for the domain that sends the mail.
The older High / Medium / Low domain and IP reputation labels retired around September 2025. A branded sending domain in Klaviyo is still how SPF and DKIM line up with the From address. DMARC lives on the From / organization domain.
