How to Fix Poor Email Deliverability for Your Shopify Store

Why Deliverability Matters for Revenue

Email marketing generates an average of $36 for every $1 spent, but only if emails reach the inbox. An email in spam generates $0. If your deliverability rate drops from 95% to 80%, you lose 15% of your email revenue immediately, plus the compounding effect of lower engagement (which further hurts deliverability in a negative feedback loop).

Transactional emails are equally affected. Order confirmations, shipping notifications, and password resets that land in spam create customer service nightmares. Customers who do not receive their order confirmation think the purchase failed. Customers who miss shipping updates flood your support with WISMO tickets. Deliverability is not just a marketing issue — it is operational infrastructure.

Email Authentication (SPF, DKIM, DMARC)

Email authentication proves to receiving mail servers that your emails are legitimately from your domain, not from a spammer pretending to be you. Without authentication, email providers are more likely to mark your messages as spam.

SPF (Sender Policy Framework): A DNS record that lists which mail servers are authorized to send email on behalf of your domain. Add SPF records for Shopify and any email marketing platform you use. Your domain registrar DNS settings is where you add SPF records.

DKIM (DomainKeys Identified Mail): A cryptographic signature that verifies the email was not altered in transit. Your email platform provides a DKIM key to add as a DNS record. Both Shopify Email and third-party platforms like Klaviyo provide DKIM setup instructions.

DMARC (Domain-based Message Authentication, Reporting and Conformance): A policy that tells receiving servers what to do with emails that fail SPF or DKIM checks. Start with a monitoring policy (p=none) to collect reports, then gradually move to quarantine (p=quarantine) and eventually reject (p=reject) as you verify all legitimate sending sources are authenticated.

Fix: Set up all three authentication records for your sending domain. If you use a custom domain email (hello@yourstore.com), the records go on yourstore.com DNS. If you send from your Shopify domain, Shopify handles basic authentication, but custom domain email requires manual setup at your registrar. See our domain setup guide for DNS configuration.

List Hygiene and Cleaning

Sending to invalid, inactive, or unengaged email addresses hurts deliverability. High bounce rates signal to email providers that you are not managing your list, which lowers your sender reputation.

Remove hard bounces immediately: Hard bounces (invalid email addresses) should be removed from your list after the first occurrence. Most email platforms do this automatically. Verify your platform handles hard bounce removal.

Suppress unengaged subscribers: Subscribers who have not opened or clicked an email in 90-120 days are dragging down your engagement metrics. Move them to a re-engagement segment and run a win-back campaign. If they still do not engage after the win-back, suppress them from regular campaigns.

Regular list cleaning: Use an email validation service (like ZeroBounce, NeverBounce, or Mailgun Validate) to verify your list quarterly. These services identify invalid addresses, spam traps, and risky addresses before you send to them.

Double opt-in: Require new subscribers to confirm their email address by clicking a link in a confirmation email. This ensures only valid, interested addresses enter your list. It reduces list growth rate slightly but dramatically improves list quality and deliverability.

Reducing Spam Complaints

Spam complaints occur when a recipient clicks the "Report spam" button in their email client. Gmail, Yahoo, and other providers track complaint rates per sender. Rates above 0.1% (1 complaint per 1,000 emails) trigger deliverability penalties.

Easy unsubscribe: Make the unsubscribe link prominent and functional. A one-click unsubscribe is better than a multi-step process. Customers who cannot easily unsubscribe report spam instead, which is much worse for your reputation.

Send relevant content: Complaints spike when subscribers receive content they did not expect or do not find valuable. If someone signed up for product updates, do not send them daily promotional emails. Segment your list and send content that matches each segment expectations.

Set expectations at signup: When collecting email addresses (through popups or checkout), clearly state what subscribers will receive and how often. "Weekly deals and new product announcements" sets expectations. Capture emails effectively with EA Email Popup & Spin Wheel which gamifies signup while setting clear expectations.

Sender Reputation Management

Your sender reputation is a score that email providers assign based on your sending behavior. High reputation means inbox delivery; low reputation means spam or blocked.

Consistent sending volume: Sudden spikes in sending volume (going from 1,000 to 50,000 emails in a day) trigger spam filters. Maintain consistent volume and gradually increase when growing your list.

Engagement-based sending: Prioritize sending to subscribers who regularly open and click your emails. High engagement rates improve your reputation. Low engagement rates (sending to large lists with low open rates) hurt it.

Dedicated sending domain: If you send high volume, use a dedicated subdomain (mail.yourstore.com) for marketing emails. This isolates marketing reputation from transactional email reputation. If marketing reputation drops, your transactional emails (order confirmations) are not affected.

Content Optimization for Deliverability

Avoid spam trigger words: Words like "FREE!!!," "ACT NOW," "GUARANTEED," excessive capitalization, and multiple exclamation marks trigger spam filters. Write naturally and avoid aggressive promotional language.

Balance text and images: Emails that are entirely images (no text) are flagged by spam filters because spammers use images to evade content scanning. Maintain at least a 60/40 text-to-image ratio.

Include a physical address: CAN-SPAM and similar regulations require a physical mailing address in every marketing email. Include your business address in the email footer. This is also a trust signal for spam filters.

Personalization: Personalized emails (using the subscriber name, referencing past purchases) have higher engagement rates, which improves deliverability. Generic batch-and-blast emails have lower engagement, hurting reputation over time.

IP and Domain Warming

When you start sending from a new IP address or domain (like when switching email platforms), you need to "warm" it by gradually increasing volume. Sending a large volume from a cold IP triggers spam filters.

Warming schedule: Start by sending to your most engaged subscribers (recent openers and clickers) at low volume (100-500 per day). Increase volume by 25-50% every 2-3 days. Over 2-4 weeks, ramp up to full volume. This builds a positive reputation before scaling.

Shared vs. dedicated IPs: Shopify Email and most email platforms use shared IPs (multiple senders share the same IP). Your deliverability depends partly on other senders behavior. High-volume merchants should consider platforms offering dedicated IPs for full control over reputation.

Monitoring Deliverability Metrics

Key metrics: Delivery rate (should be above 95%), open rate (benchmark 20-30% for ecommerce), bounce rate (should be below 2%), spam complaint rate (must stay below 0.1%), and unsubscribe rate (healthy is below 0.5% per campaign).

Google Postmaster Tools: If a significant portion of your subscribers use Gmail, set up Google Postmaster Tools for your domain. It shows your domain reputation, spam rate, authentication status, and delivery errors specific to Gmail — the most important email provider to get right.

Regular testing: Send test emails to accounts at major providers (Gmail, Yahoo, Outlook, Apple Mail) before each campaign to verify inbox placement. Tools like Mail Tester (mail-tester.com) score your email setup and identify specific deliverability issues.

Deliverability Testing Tools

Mail Tester (mail-tester.com): Free tool that scores your email on a 10-point scale, checking authentication, content, blacklists, and more. Send a test email to their unique address and get an instant report.

MXToolbox: Checks your domain for blacklist status, SPF/DKIM/DMARC configuration, and DNS health. Essential for diagnosing authentication problems.

Google Postmaster Tools: Free monitoring dashboard for Gmail deliverability. Shows domain reputation, spam rate, and authentication results over time.

Frequently Asked Questions