Shopify Email Deliverability Guide: Land in the Inbox, Not Spam

Your Email Revenue Depends on Deliverability

If your emails land in spam, they don’t exist. With Gmail and Outlook increasingly aggressive about filtering promotional emails, deliverability is the invisible foundation of email marketing revenue. A store with 30% open rates and good deliverability earns far more from email than one with 20% open rates where 20% of sends never reach the inbox at all.

Technical Deliverability Setup

• Custom sending domain — send email from [email protected], not a shared Klaviyo/Mailchimp domain. Shared sending domains have shared reputation — someone else’s spam sending damages your deliverability.
• SPF record — a DNS record that tells receiving mail servers which servers are authorised to send email on behalf of your domain. Add your email platform’s SPF record to your DNS.
• DKIM signature — cryptographic signature that proves your emails haven’t been tampered with in transit. Enable DKIM in your email platform settings and add the DNS records provided.
• DMARC policy — tells receiving servers what to do with emails that fail SPF/DKIM checks. Start with p=none (monitor mode) then advance to p=quarantine or p=reject once you’ve verified legitimate sends are passing authentication.
• Google Postmaster Tools — free Google tool that shows your domain reputation and spam rate as Gmail sees it. Set up if you have significant Gmail subscribers.

List Hygiene for Deliverability

Inbox providers (Gmail, Outlook, Yahoo) use engagement signals to filter emails. Sending to many unengaged recipients tells these providers your emails aren’t wanted — which affects deliverability across your entire list, including the engaged segment. Suppress every 90 days:

• Hard bounces — immediately (email addresses that don’t exist)
• Soft bounce repeats — after 3 consecutive soft bounces
• Non-openers past 180 days — after a win-back attempt

Content That Avoids Spam Filters

• Avoid spam trigger words in subject lines: “FREE!!!”, “Act Now”, “Limited Time Offer”, “Guaranteed”
• Maintain image-to-text ratio of roughly 60:40 (image-only emails hit spam)
• Include a plain text version of every email (email platforms do this automatically)
• Include a visible, functioning unsubscribe link
• Don’t use URL shorteners (bit.ly etc.) in email links — these are associated with spam

Warming a New Sending Domain

When you start sending from a new domain or IP address, inbox providers have no reputation data for you. Warm up gradually: Week 1: 500 sends/day to your most engaged subscribers. Week 2: 2,000/day. Week 3: 5,000/day. Increase by 2–3x each week until you reach your full volume. Sending at full volume immediately from a new domain almost guarantees spam classification.

Need an email deliverability audit for your Shopify store? Our email team handles technical setup and list hygiene. Get a free email audit or see our results.