Short answer: Klaviyo emails go to spam for five reasons: you still send from Klaviyo's shared address, you are judging by a test email that behaves differently from a real send, your account is new and you emailed everyone at once, your list is full of people who never open, or the emails look like spam. The first shows up as "via klaviyomail.com" next to your name in Gmail, and one setting removes it. Every statement below links to Klaviyo's or Google's own page, checked on 22 October 2026.
Quick answer
- "via klaviyomail.com" next to your name in Gmail → cause 1 → turn on your own branded sending domain in Klaviyo; allow 48 hours.
- Test email in spam, real sign-up in the inbox → cause 2 → trust the real send; stop testing with filler text to your own address.
- New account or domain, one big first campaign, then poor results → cause 3 → send to people who open, in smaller groups, first.
- Opens falling, bounces rising, list still growing → cause 4 → stop sending to people who have never opened.
- One big image, filler words, several emails a day → cause 5 → real text, one email a day at most, the unsubscribe block in every template.
Test emails and real sends: why they behave differently
What Klaviyo says about preview emails
The most searched version of this question is "klaviyo test email going to spam", and Klaviyo has a page for exactly that. Its reasons: filler text ("this may trigger the email client's spam filter"); previews you "never open or click", which Gmail learns from; a preview sent to an address that is also the sender or reply-to address; a sender Gmail cannot verify; and strict company filters. A preview from a saved template uses your account's contact address, a preview from a campaign or flow uses that message's own sender settings, and "sending from the template editor does not bypass the recipient's spam filters" (Klaviyo: Understanding why some preview emails go to spam, updated 21 Oct 2026, checked 22 Oct 2026).
What a test email cannot tell you
Klaviyo's testing page says that in a preview "some dynamic content does not behave the same way it does in a live send" and that "a live test is the best option" for anything that happens at send time (Klaviyo: How to preview and send test emails, updated 14 Aug 2025, checked 22 Oct 2026). And Klaviyo "can confirm whether an email was delivered to the recipient's inbox, but not where in the inbox it landed" (Klaviyo: Email deliverability FAQs, updated 31 Mar 2026, checked 22 Oct 2026).
In short: a test email in spam is a clue, not a verdict; a real sign-up email to a personal Gmail address is the honest test.
The five causes, in the order we find them
1. You still send from Klaviyo's shared address
Klaviyo says it plainly: "By default, you start out sending from a shared IP and shared Klaviyo domain." Gmail then shows "via klaviyomail.com" next to your name, and "you can inherit those shared domains' reputations", good and bad (Klaviyo: Understanding branded vs. shared sending domains, updated 7 Jul 2025, checked 22 Oct 2026). Google confirms "via" appears when the sending domain does not match your From address (Gmail: extra info next to sender's name, checked 22 Oct 2026).
The fix is a "branded sending domain": your emails sent and signed by your own domain, so only your sending affects your reputation. "Any company is eligible", Klaviyo shows you what to add where your domain is managed, and allow "up to 48 hours" (Klaviyo: How to set up a branded sending domain, updated 30 Sep 2026, checked 22 Oct 2026). Klaviyo "advises all customers to set up a branded sending domain", and recommends it in particular for accounts with 5,000 or more active profiles (Klaviyo: Email deliverability best practices reference, updated 18 Feb 2026, checked 22 Oct 2026).
The sign: "via klaviyomail.com" next to your brand name in Gmail. The first move: turn on your branded sending domain in Klaviyo and give it two days. One setting, free on every plan, reversible.
In short: "via" means a shared address and a shared reputation; your own sending domain removes both.
2. You are judging by a test email
Everything in the first section applies here, plus one trap. In a flow, the test comes from "Preview & test" ("click Send test to send a preview to your own inbox", Klaviyo: How to test and preview flow messages, updated 7 Oct 2026, checked 22 Oct 2026). That shows how the email looks, not how Gmail treats the email a real subscriber receives after a real sign-up.
The sign: the test lands in spam, but a real sign-up with a fresh personal address lands in the inbox; or your "tests" all go to the address you also send from. The first move: run the real send once, as a customer would, and judge by that.
In short: test the layout with a test send; test the inbox with a real sign-up.
3. Your account or domain is new and you emailed everyone at once
Inbox providers trust a sender they know. Klaviyo calls the period of proving yourself "warming" ("establishing a reputation as a legitimate or 'good' email sender") and calls a domain "cold" if it was registered in the last 30 days or has never sent email (Klaviyo: Understanding ramping vs. warming, updated 7 Jul 2025, checked 22 Oct 2026). Its advice: "create and send only to engaged segments", start low, increase gradually, send consistently (Klaviyo deliverability reference, checked 22 Oct 2026), and "warming should be a minimum of 30 days with good performance" (Klaviyo: Email deliverability FAQs, checked 22 Oct 2026). Stopping altogether means starting again.
The sign: a new account or a fresh sending domain, one big campaign to the whole list, then opens drop and stay down. The first move: smaller, steady sends to the people who already open and buy, before anyone else. The exact plan depends on your list and season, which is why it is a project, not a setting.
In short: a new sender has no reputation yet; earn it with engaged people first, and do not stop halfway.
4. People who never open
Klaviyo's troubleshooting page says your reputation is built from engagement, volume, bounces, complaints and unsubscribes, and that mailing people who never engage lowers it. Its first move is "creating and then suppressing a segment of subscribers who have never engaged", after a fair chance (at least five emails in 180 days). Its targets: bounces under 1%, spam complaints under 0.01%, unsubscribes under 0.3% per campaign (Klaviyo: Troubleshooting why emails go to spam, updated 21 Oct 2026, checked 22 Oct 2026). Google's line: a spam rate below 0.3%, ideally under 0.1% (Gmail sender guidelines, checked 22 Oct 2026). Never a bought list.
The sign: the list keeps growing while opens fall and bounces rise. The first move: stop sending to anyone who has never opened.
In short: a list that grows while opens fall needs fewer recipients, not more sending.
5. Emails that look like spam: image-only, filler, too many a day
Content is what everyone checks first and is rarely the whole story, which is why it sits last. Klaviyo says "emails that consist solely of GIFs and images (or are very image-heavy) may trigger spam filters", that spammy subject lines count against you, and that "any more than 1 email per inbox per day is risky" (Klaviyo: Troubleshooting why emails go to spam, checked 22 Oct 2026). Klaviyo adds the one-click unsubscribe Google asks for automatically (Klaviyo: unsubscribes, updated 18 Mar 2026, checked 22 Oct 2026); your job is the visible link in every template, because a subscriber who cannot find it presses "Report spam" instead.
The sign: your last campaign was one big picture, or a sale week meant three emails a day. The first move: real text for the headline, the offer and the button; one email a day at most; the unsubscribe block in every template.
In short: text first, one email a day, unsubscribe visible; content alone is rarely why you are in spam.
The two-minute test for Klaviyo
Do it twice, to the same personal Gmail address (not a work account): first a test from your welcome flow's "Preview & test", then the real thing, a sign-up through your shop's form or a real campaign to a small group that includes you. Compare the two emails on four questions.
1. Which folder did each one land in?
Both in the inbox: good. Test in spam, real one in the inbox: cause 2; stop worrying about the test. Both in spam: at least one of causes 1, 3 and 4 is yours.
2. Is there "via klaviyomail.com" next to your name?
Yes means cause 1. Fix this first, whatever else you find.
3. Is there a "Powered by Klaviyo" line at the bottom?
Then you are on the free plan: 250 profiles, 500 emails a month, 3 automations live, 1 live form, and that line until you upgrade (Klaviyo: free plan limits in Klaviyo Starter in Shopify, updated 21 Sep 2026, checked 22 Oct 2026). Klaviyo's pages do not list it as a spam cause, and your own sending domain is available on every plan: what matters is the address above it, not the badge below. The free plan does cap previews at 100 per billing cycle (Klaviyo: How to preview and send test emails, checked 22 Oct 2026).
4. Is there an unsubscribe link in the footer?
No means cause 5. That is as far as two minutes can take you; causes 3 and 4 live in your numbers over weeks, not in one email.
What to fix first
1. Turn on your own sending domain
Cause 1, and the setting Klaviyo itself recommends for every account. One change, free on every plan, up to 48 hours to take effect, reversible.
2. Send to the people who open
Causes 3 and 4. Engaged people first and the never-engaged out; a new sender earns trust with its best readers, not its biggest list.
3. Keep the unsubscribe, and the text
Cause 5. The unsubscribe block in every template, real words for the headline and the offer, one email a day at most.
Setup changes show within two days; a new or damaged reputation takes weeks of steady sending to engaged subscribers.
When to get help
The "via" label is gone and real emails still land in spam
Then the cause is reputation, which needs a plan over weeks, not a setting. Send us your shop's address for a free email health check and we reply with the three fixes that matter most, clear and simple, no obligation. More about our email deliverability service.
Your account is new and a busy season is coming
Warming, the first flows and your sending domain need to happen in the right order before the season, not during it. That is what our Klaviyo Launch Pack does, with a fixed quote after a free check (how our pricing works). Still choosing a platform? Read Klaviyo vs Mailchimp for Shopify shops; the causes shared by every tool are in why Shopify emails go to spam.
Common questions
Why does my Klaviyo test email go to spam when the real email does not?
Klaviyo's help page on preview emails lists the usual reasons: filler text in the draft, previews sent to an address that is also the sender or reply-to address, previews you receive often but never open (Gmail learns from that), strict company filters, and a sender that cannot be verified. A test send is for checking the layout; the real sign-up email is the honest test of where your emails land.
Why does Gmail show "via klaviyomail.com" next to my shop's name?
By default Klaviyo sends from a shared Klaviyo domain, so Gmail shows "via klaviyomail.com" next to your name and your reputation is shared with every other brand on that domain. Setting up your own branded sending domain in Klaviyo removes the label; Klaviyo says to allow up to 48 hours.
Does the free Klaviyo plan send to spam more than a paid plan?
Klaviyo's pages do not say that. The free plan adds "Powered by Klaviyo" to your emails and forms and caps you at 250 profiles, 500 emails a month, 3 live automations and 1 live form, but the things that decide inbox placement, your sending address, your list and your content, are the same on every plan. Any account can set up its own sending domain.
Can Klaviyo tell me if my email went to spam?
No. Klaviyo says it can confirm whether an email was delivered to the recipient, but not where in the inbox it landed. The quickest honest check is a real sign-up to your own list with a personal Gmail address, then looking at which folder the welcome email arrives in.
How long until my Klaviyo emails reach the inbox again?
A sending-domain change takes effect within hours; Klaviyo says to allow up to 48 hours. If your account or domain is new, Klaviyo says the warming period, the time it takes to prove you are a good sender, should be a minimum of 30 days with good performance, so expect weeks, not days.