Klaviyo inbox placement testing shows where a real campaign lands after Klaviyo sends it. MailSlurp supplies controlled Gmail, Google Workspace, Outlook, and Microsoft 365 seed addresses, matches the delivered message using a unique test marker, and reports the folder result for each provider. Klaviyo can report that an email was delivered, but its [deliverability FAQ](https://help.klaviyo.com/hc/en-us/articles/16425927010075) explains that delivery alone does not identify the folder or tab where the message landed. A seed-based placement test closes that gap. Use the observed provider results together with MailSlurp's content and domain checks when investigating spam placement or preparing an important campaign. ## Quick answer To test Klaviyo inbox placement and spam signals: 1. Create a new inbox placement test in MailSlurp. 2. Copy the unique marker and all four provider seed addresses. 3. Import the seeds into a dedicated Klaviyo list with email marketing consent. 4. Create or clone a Klaviyo email campaign for that list. 5. Put the exact marker in the subject or message body. 6. Confirm that the campaign has four eligible recipients. 7. Send the campaign immediately. 8. Review the Gmail, Google Workspace, Outlook, and Microsoft 365 placement rows. 9. Inspect the **Content issues** and **Domain issues** tabs before retesting. Create a new MailSlurp run for every campaign revision. A marker from an earlier run will not reliably associate the new message with the intended result. {{LANDING_SHORTCODE:POST_CTA_BANNER:%7B%22title%22%3A%22Measure%20Klaviyo%20campaign%20placement%20before%20launch%22%2C%22content%22%3A%22Send%20the%20final%20Klaviyo%20campaign%20to%20controlled%20provider%20inboxes%2C%20then%20compare%20real%20folder%20placement%20and%20campaign%20health%20signals.%22%2C%22buttonHref%22%3A%22https%3A%2F%2Fapp.mailslurp.com%2Fobserve%2Finbox-placement%22%2C%22buttonText%22%3A%22Start%20an%20inbox%20placement%20test%22%2C%22buttonTheme%22%3A%22blue%22%2C%22image%22%3A%22%2Fassets%2Fhome%2Finbox-placement-ui.png%22%2C%22imageAlt%22%3A%22Email%20deliverability%20and%20inbox%20placement%20results%22%2C%22imageWidth%22%3A%22800%22%2C%22imageHeight%22%3A%22548%22%2C%22imagePosition%22%3A%22%22%7D}} ## Before you begin Prepare the Klaviyo email you want to test and confirm that its sender identity and sending domain are ready. You need permission to create or import profiles, apply email consent, create a list, edit a campaign, and send it. Use a dedicated list such as `MailSlurp Inbox Placement Seeds`. Do not mix seed addresses into a customer segment or use the test campaign for production recipients. ## Step 1: Create a MailSlurp inbox placement test Open **Deliverability**, select **Inbox placement**, and create a new test. Copy the unique marker and every seed address shown for the run. The marker can appear in the subject or body. Putting it in the subject makes the final Klaviyo review screen easy to verify before the send. ## Step 2: Import the seed addresses into a Klaviyo list In Klaviyo, open **Audience** and **Lists & segments**, then create a list named `MailSlurp Inbox Placement Seeds`. Open **Manage list** and choose **Import contacts**. For four addresses, the copy-and-paste CSV option is quick and easy to review. Use columns such as: ```text Email,First Name,Last Name seed-address-1@example.com,Gmail,Personal Seed seed-address-2@example.com,Outlook,Personal Seed ``` Paste every address from the active MailSlurp run, map the email and name columns, and continue. Klaviyo's [subscriber import instructions](https://help.klaviyo.com/hc/en-us/articles/115005251128) explain the same list import and column-mapping flow. ## Step 3: Apply email consent and verify the list When Klaviyo asks whether the imported contacts subscribed to messaging, select **Yes**, choose **Email**, apply marketing consent, and import the profiles. This permits the controlled test send; it does not turn the provider seeds into customer records. Open the completed list and confirm that it contains all four provider profiles. ![Klaviyo list with arrows showing the dedicated MailSlurp seed list and all four provider profiles](/assets/guides/klaviyo-inbox-placement-testing/01-klaviyo-seed-list.webp) The list count must match the number of addresses in the current MailSlurp test. If Klaviyo suppresses or excludes a profile, the placement result for that provider will not represent a send attempt. ## Step 4: Create or clone a Klaviyo campaign Open **Campaigns** and create an email campaign, or clone a suitable draft so the test uses realistic content. Select `MailSlurp Inbox Placement Seeds` as the only recipient list. Klaviyo's [campaign instructions](https://help.klaviyo.com/hc/en-us/articles/115005054847) recommend checking the expected recipient count after duplicate, exclusion, and suppression rules are applied. For this test, the final eligible count should be four. Turn off Smart Sending for the placement campaign if it would skip a seed that recently received another test. Leave production frequency controls unchanged outside this dedicated QA campaign. ## Step 5: Add the unique marker to the message Enter the exact MailSlurp marker in the subject or message body. A clear subject format is: ```text Klaviyo Inbox Placement QA | mip-example123 ``` Keep the sender name, sender address, reply-to address, links, images, footer, and unsubscribe content representative of the campaign you plan to launch. A simplified placeholder message may produce a result that does not reflect the final creative. ## Step 6: Review and send the campaign On Klaviyo's **Review** step, confirm the following before selecting **Schedule or send**: - the recipient card shows four profiles - the marked subject belongs to the current MailSlurp run - the message section is complete - the intended sender name and email address are present - no recipient warning will remove a provider seed ![Klaviyo campaign review with arrows showing four profiles, the placement marker, and the Schedule or send action](/assets/guides/klaviyo-inbox-placement-testing/02-klaviyo-send.webp) Choose **Send now**, confirm the send, and leave the MailSlurp result open. Klaviyo may show the campaign as scheduled briefly while it determines recipients and queues the immediate send. ## Step 7: Read the provider placement results MailSlurp updates the run as provider inboxes receive and classify the message. Each row shows the seed inbox, folder placement, provider, audience type, and receive time. ![MailSlurp result for a Klaviyo campaign with arrows showing the delivery score, provider placement rows, and issue tabs](/assets/guides/klaviyo-inbox-placement-testing/03-klaviyo-placement-result.webp) The worked test above used the same Klaviyo campaign and marker shown in the review step and finished with a delivery score of 60. Gmail Personal and Google Workspace Business reached Promotions, Outlook Personal reached Spam, and Microsoft 365 Business reached Focused. This provider split is a reason to investigate, not a universal prediction for every subscriber. Interpret each label as an observed outcome: | Result | What it means | | ---------------- | ------------------------------------------------------------------------------------------ | | Primary or inbox | The message reached the main inbox experience for that seed | | Promotions | The provider delivered the message to a promotional category rather than the primary view | | Spam or junk | The provider classified the message as unwanted or suspicious | | Not received | MailSlurp did not observe the message at that seed during the test window | | Timed out | MailSlurp did not observe a provider result before the run finished | | Pending | The provider result is still being checked | Promotions is delivered, but it is not primary placement. Decide whether that category is suitable for the campaign's purpose and audience. ## Step 8: Review content and domain issues Open **Content issues** for message-level findings, then open **Domain issues** for authentication, reputation, and sending-domain checks associated with the run. Prioritize specific, measurable improvements: - authenticate the sending domain with SPF, DKIM, and DMARC - keep the visible sender and reply handling consistent - remove broken, misleading, or unnecessary links - use meaningful image alternative text and balanced message content - send to permissioned, engaged recipients - avoid sudden or unexplained volume changes - keep unsubscribe and preference controls clear - create a new placement run after changing the campaign Change one meaningful variable at a time. That makes the next provider result easier to compare with the previous run. ## Klaviyo inbox placement checklist Before treating a run as valid, confirm: - the marker belongs to the active MailSlurp run - all four current seed addresses are in the dedicated Klaviyo list - email marketing consent is present for every seed profile - the expected recipient count is four after exclusions and suppressions - Smart Sending will not skip a seed - the message uses the intended sender and sending domain - Klaviyo queued or sent the immediate campaign - the MailSlurp rows belong to the current run - pending providers have been allowed to finish - content and domain issues have been reviewed ## Troubleshooting Klaviyo placement tests ### MailSlurp does not recognize the campaign Confirm that the exact active marker appears in the subject or body of the email Klaviyo sent. If the wrong draft or marker was used, create a fresh MailSlurp run, update the campaign, and send to the new seed set. ### Klaviyo shows fewer than four recipients Check the list member count, consent status, suppressions, exclusions, duplicate profiles, and Smart Sending. The campaign's eligible recipient count is the value that matters at send time. ### A provider stays pending Wait for the observation window to complete. Do not convert a pending row into an assumed inbox or spam result. A later not-received or timeout result is useful evidence of what the test observed. ### Gmail lands in Promotions Promotions is a delivered category. Compare that outcome with the campaign's purpose, then review the content and domain findings before changing the message. Retest the complete revised campaign rather than relying on a single subject-line change. ### Outlook lands in spam Review sender authentication, domain reputation, recent volume, list quality, and the exact message content. Fix a concrete issue, create a new MailSlurp run, and send the revised campaign to all four current seeds. ### Klaviyo reports delivered but MailSlurp shows spam These results answer different questions. Delivered means the receiving system accepted the message; the MailSlurp row reports where the provider placed the received copy. ## FAQ ### How do I test Klaviyo inbox placement? Create a MailSlurp inbox placement run, import its provider seeds into a dedicated opted-in Klaviyo list, put the unique marker in the campaign, send to the four eligible profiles, and review the provider rows. ### Can I test a Klaviyo email for spam before sending it to customers? Yes. Send the final campaign to the controlled MailSlurp seed list first. Review observed spam, promotions, inbox, or not-received outcomes together with content and domain issues. ### Is Klaviyo deliverability the same as inbox placement? No. Deliverability records whether a receiving system accepted a message. Inbox placement records the folder or category where the received copy appeared for the test seed. ### Should I use a list or segment for the seed addresses? A dedicated list is straightforward for a fixed four-address test because you can verify the exact members before sending. Keep the list separate from customer audiences. ### Can I reuse the Klaviyo seed list? You can reuse the list name and campaign pattern, but replace its members with the addresses supplied by the current MailSlurp run and use the new marker every time. Start with the [inbox placement documentation](/docs/inbox-placement/) for the dashboard workflow. To approve the same campaign's visual layout, follow the [Klaviyo Gmail, Outlook, iPhone, and Android preview guide](/guides/klaviyo-device-rendering/).