How to Stop Your Shopify Emails Landing in Spam (2026 Guide)

If your Shopify email campaigns are reaching your subscribers' spam folders, you are not just losing sales on that send, you are damaging the sender reputation that determines whether every future email you send gets delivered at all. Email providers like Gmail, Outlook, and Yahoo make filtering decisions based on a stack of technical checks, behavioural signals, and reputation data, and a store that fails even one of them can find its entire sending domain quietly blacklisted.

This guide covers every major spam-prevention layer email providers use in 2026, why it matters for Shopify merchants specifically, and the exact steps to make sure you are on the right side of each one. If you are also looking to grow your list or improve your overall email strategy, our guides on how to get more Shopify email subscribers and how to optimise your Shopify email marketing cover both in full.

Why Spam Filtering Matters More for Shopify Stores in 2026

Email providers do not just filter obvious junk. They evaluate every sender's technical setup, sending history, and the behaviour of their recipients. A Shopify merchant sending legitimate promotional emails can still land in spam if their domain authentication is missing, their list contains too many inactive addresses, or their spam complaint rate creeps above 0.1%. Google and Yahoo tightened their bulk sender requirements in 2024, making authentication and one-click unsubscribe mandatory rather than best practice. Stores that have not implemented these changes are already at risk.

The good news is that every layer below is fixable, and most fixes are one-time technical tasks rather than ongoing work.

1. SPF (Sender Policy Framework) Authentication Email providers check the sending server's IP address against a published DNS record, called the SPF record, that lists all IP addresses authorised to send email on behalf of your domain. If an email arrives from an unlisted IP, it is flagged as likely spoofed or unauthorised and routed to spam, or rejected outright.

What to do: Log into your domain registrar (such as GoDaddy, Namecheap, or Cloudflare) and add an SPF TXT record to your DNS settings. If you send through Klaviyo, the record should include their sending servers. A typical example looks like this: v=spf1 include:klaviyo.com include:_spf.google.com ~all. Most email platforms provide a ready-made SPF record in their settings under Domain Authentication.

2. DKIM (DomainKeys Identified Mail) Authentication Every outgoing email is cryptographically signed using a private key held by the sending platform. The receiving server looks up the corresponding public key in your DNS records and verifies the signature. This confirms the email genuinely came from your domain and has not been altered in transit.

What to do: Your email platform, whether Klaviyo, Mailchimp, or another, will provide you with a DKIM record to add to your domain's DNS. This is usually found under Settings, then Domains or Sending Domains. Add it to your DNS and click Verify in the platform. Without this step, your emails will almost certainly land in spam regardless of how good the content is.

3. DMARC (Domain-based Message Authentication, Reporting and Conformance) DMARC builds on SPF and DKIM by allowing you to publish a policy instructing receiving servers on what to do if an email fails both authentication checks: nothing (monitor only), quarantine it to the spam folder, or reject it outright. It also generates reports back to you about who is sending email on your behalf, exposing any spoofing attempts using your domain.

What to do: Once SPF and DKIM are in place, add a DMARC TXT record to your DNS. A safe starting policy is: v=DMARC1; p=none; rua=mailto:you@yourdomain.com. This monitors without rejecting anything, and sends you aggregate reports. Once you are confident all legitimate sends are authenticated, move to p=quarantine and eventually p=reject. Google and Yahoo have required at least a p=none DMARC record for bulk senders since 2024.

4. Spam Content Filtering Email providers scan the body, subject line, and headers of every email against libraries of known spam patterns. These include excessive use of trigger words such as FREE!!!, CLICK NOW, or YOU HAVE WON, all-caps subject lines, excessive punctuation, misleading subject lines that do not match the email body, hidden text, suspicious HTML, and a high image-to-text ratio with little readable copy.

What to do: Write subject lines that describe what is actually in the email. Avoid excessive punctuation or capitalisation. Keep a healthy balance of text to images, aiming for at least 60% readable text. Before sending any campaign, run it through a free spam checker. Mail-Tester is particularly useful: you send an email to the address they provide, and they score your message for spam indicators, authentication (SPF, DKIM, DMARC), and content quality. GlockApps (free tier available) goes further, testing placement across multiple mailbox providers simultaneously so you can see how your email performs across Gmail, Outlook, Yahoo, and others before it goes to your full list.

5. Sender Reputation Scoring Every sending IP address and domain accumulates a reputation score based on historical sending behaviour. Factors that lower reputation include high bounce rates, high spam complaint rates, sending to spam trap addresses, and sudden large volume spikes. Email providers consult reputation data from third-party services as well as their own proprietary systems when making filtering decisions.

What to do: Maintain a clean list (covered in point 7 below). Never purchase email lists. Warm up a new sending domain gradually, starting with small volumes to your most engaged subscribers before sending to your full list. Keep your spam complaint rate below 0.1%. Google's threshold for bulk senders is 0.08% before warnings begin. If you use a reputable email service provider like Klaviyo, your sending IP is managed and warmed by them, which is one key advantage of using an established platform.

6. Engagement-Based Filtering Gmail in particular weights recipient behaviour heavily when deciding where to deliver email. If a subscriber consistently opens, clicks, and does not mark emails as spam, Gmail learns to deliver future emails to the inbox. If a subscriber never opens emails over many months, Gmail may start routing them to spam or the promotions tab, regardless of how well-authenticated your domain is.

What to do: Segment your list regularly and suppress unengaged subscribers before they damage your sender reputation. In Klaviyo, build a segment of subscribers who have not opened or clicked in the last 90 to 120 days and either run a re-engagement campaign or remove them from your active sends. Sending to a smaller, engaged list always outperforms sending to a large, disengaged one, both in revenue and in deliverability. For more on segmentation strategy, see our Shopify email marketing optimisation guide.

7. List Hygiene and Bounce Management Hard bounces, meaning permanent delivery failures where the email address does not exist, are a strong negative signal to email providers. A high bounce rate suggests you are using an old, purchased, or poorly maintained list, which is a hallmark of spammers. Providers track bounce rates as a core component of sender reputation.

What to do: Use a double opt-in process so that only real, confirmed email addresses enter your list. Most email service providers automatically suppress hard bounces, make sure this feature is enabled. Periodically validate your list using a tool such as ZeroBounce or NeverBounce, which checks addresses against known invalid and disposable domains before you send. For tips on building a quality list from the start, see our guide on how to get more Shopify email subscribers.

8. Spam Trap Detection Email providers and anti-spam organisations seed the internet with spam trap addresses, which are email addresses that never opted in to anything and exist solely to catch senders who are scraping or purchasing lists. Hitting even a small number of spam traps can severely damage your sender reputation and trigger blacklisting.

What to do: Never purchase, rent, or scrape email lists. Only send to subscribers who have actively opted in to receive email from you, ideally via a double opt-in confirmation. Remove long-inactive subscribers from your list rather than continuing to send to them, as recycled spam traps are often created from abandoned email addresses.

9. Unsubscribe Compliance (List-Unsubscribe Header) Gmail, Yahoo, and others require bulk senders to include a one-click unsubscribe mechanism via the List-Unsubscribe header, which powers the Unsubscribe link shown natively at the top of an email in the Gmail interface. As of 2024, both Google and Yahoo require one-click unsubscribe for bulk senders, defined as those sending over 5,000 emails per day. Senders who make it difficult to unsubscribe see sharply higher spam complaint rates, because users simply mark as spam instead.

What to do: Use a reputable email service provider. Klaviyo, Mailchimp, and most modern platforms automatically include the List-Unsubscribe header and manage opt-outs. Never suppress or hide the unsubscribe link in your email template. Process unsubscribes promptly. Making the unsubscribe link difficult to find means users will mark you as spam instead, which damages your sender reputation far more than a lost subscriber.

10. Machine Learning and AI-Based Filtering Gmail and other providers use machine learning models trained on billions of emails to identify spam patterns that no static rule could catch. These models learn from aggregate user behaviour. When many users mark a similar email as spam, or when an email shares structural characteristics with known spam, the model scores it accordingly. AI filtering can catch novel spam campaigns within hours of their first appearance.

What to do: There is no direct technical countermeasure to AI filtering, because it fundamentally rewards genuinely wanted email. The best defence is sending relevant, personalised content to people who chose to hear from you. Use segmentation to match content to subscriber interest. A transactional email such as an order confirmation or shipping update almost never lands in spam. A generic promotional blast to an unsegmented list is the highest-risk scenario.

11. Blacklist Monitoring There are dozens of third-party IP and domain blacklists, including Spamhaus, SORBS, and Barracuda, that email providers consult when deciding whether to accept mail. A sending IP or domain can be added to a blacklist after a spam complaint spike, hitting spam traps, or being reported. Once blacklisted, virtually all email from that IP or domain will be blocked or sent to spam across every provider that consults the relevant list.

What to do: Monitor your domain and sending IP regularly using MXToolbox, which checks your domain against over 100 blacklists simultaneously and is free to use. Set a monthly calendar reminder to check. If you are listed, follow the blacklist's delisting process, usually a form on their website, and resolve the underlying sending issue before applying. If you use a shared sending IP through your email service provider, blacklisting of that IP affects all senders on it, which is another reason to use a reputable, well-managed platform.

12. BIMI (Brand Indicators for Message Identification) BIMI is a standard that allows brands to display their logo in the Gmail inbox next to authenticated emails. While primarily a trust and branding tool rather than a spam filter, it requires a verified DMARC policy at enforcement level (p=quarantine or p=reject) and a Verified Mark Certificate, meaning only well-authenticated, properly configured senders can display it. Its presence acts as a positive trust signal with subscribers.

What to do: BIMI is an advanced step, not a day-one priority. The prerequisites are SPF, DKIM, and DMARC all correctly implemented at p=quarantine or p=reject level, a trademarked logo in SVG format, and a Verified Mark Certificate from a provider such as DigiCert or Entrust. Get your authentication stack right first, then BIMI is a relatively straightforward addition that can meaningfully improve inbox brand visibility.

The Free Tools Worth Bookmarking These three tools cost nothing and cover the most important ongoing checks a Shopify merchant should run:

MXToolbox — checks your domain and sending IP against over 100 blacklists simultaneously, verifies your SPF, DKIM, and DMARC records, and flags any DNS misconfigurations. Run this monthly. Mail-Tester — send an email to the address they provide and they score your message for spam indicators, authentication, and content quality. Use this before every major campaign send. GlockApps (free tier) — tests email placement across multiple mailbox providers including Gmail, Outlook, and Yahoo simultaneously, so you can see exactly where your emails land before sending to your full list. If you send from your own domain, you should also set up Google Postmaster Tools, which is free and gives you direct visibility into how Gmail rates your domain's reputation, your spam rate as measured by Gmail users, and your authentication pass rates. It is the closest thing available to seeing your sender score directly from Google's perspective.

FAQ Why are my Shopify emails going to spam even though I have not done anything wrong? The most common reasons are missing or misconfigured SPF, DKIM, or DMARC records, a list with too many unengaged or invalid addresses, or a spam complaint rate that has crept above Gmail's 0.08% threshold. Run your domain through MXToolbox and your last campaign through Mail-Tester to identify the specific issue.

Is it enough to just set up SPF and DKIM? SPF and DKIM are the foundation and both are essential, but DMARC is also now required by Google and Yahoo for bulk senders. Without a DMARC record, even a correctly authenticated email can be treated with more suspicion. All three work together as a system, not as alternatives.

How do I know if my Shopify store is on an email blacklist? Use MXToolbox's free blacklist checker, which tests your domain and sending IP against over 100 blacklists simultaneously. If you are listed, follow the delisting process on the relevant blacklist's website and fix the underlying issue (usually high complaint rates or hitting spam traps) before applying.

Do I need to set these things up if I use Klaviyo? Klaviyo manages your sending IP and handles many deliverability best practices automatically, but domain authentication (SPF, DKIM, DMARC) must be set up on your own domain's DNS. Klaviyo provides the exact records to add under Settings, then Sending Domains. Until you add them, your emails send from Klaviyo's domain rather than yours, which limits the trust signals your domain can build over time.

What spam complaint rate is considered safe for a Shopify email sender?![]() Google's published threshold is 0.08% before warnings begin, and 0.3% before delivery is impacted. In practice, aim to stay below 0.05% on every send. If a campaign triggers a complaint rate above 0.1%, suppress the segment it was sent to and investigate the content or targeting before sending again. Google Postmaster Tools shows you your spam rate as measured directly by Gmail users, making it the most reliable indicator available.

For the broader picture on how email marketing fits into your Shopify growth strategy, see our guide on how to optimise your Shopify email marketing, and if you are still building your list, start with how to get more Shopify email subscribers.