If your reminder emails are landing in spam or the Promotions tab instead of the inbox, here's how to diagnose and fix it.
🌐 1. Set up a custom sending domain (the big one)
The single most impactful fix is sending from your own domain (e.g., [email protected]) instead of the shared default sender.
When emails come from your custom domain:
📈 Deliverability improves significantly
🔒 SPF and DKIM authentication signal you're a legitimate sender
🤝 Customers see emails clearly from your brand
See the "Set Up a Custom Sending Domain" article for the step-by-step setup. If you haven't done this yet, do it first — it usually resolves 80% of deliverability issues.
📧 2. Avoid spam-triggering content
Email providers like Gmail, Outlook, and Yahoo use content-based filters that flag certain words and patterns as spammy:
❌ All-caps in subject lines ("REORDER NOW!")
❌ Excessive exclamation points ("BEST DEAL!!! BUY NOW!!!")
❌ Spammy phrases like "FREE", "100% off", "act now"
❌ Tons of emoji in the subject line (some is fine; 5+ is suspicious)
❌ Links that look unrelated to the domain you're sending from
Rewrite your subject lines and body copy to sound like a friend would write it — natural, conversational, not pitchy.
🎨 3. Balance text and images
Emails that are mostly images with very little text get flagged. Make sure your design has:
Real, readable text (not text inside an image)
A reasonable image-to-text ratio (roughly 60% text, 40% image is a safe guideline)
Alt text on all images
📨 4. Ask customers to mark you as "Not Spam"
If a few customers report your emails going to spam, ask them to:
Open the email in spam/junk
Click "Not Spam" or "Move to Inbox"
Add your sender address to their contacts
Each "Not Spam" signal you collect helps your sender reputation across all customers on that email provider.
🛡️ 5. Build sender reputation gradually
If you just set up a custom sending domain and started sending in volume, your domain has no reputation yet. Email providers treat new domains skeptically.
To build reputation:
📈 Ramp up volume gradually — don't go from 0 to 10,000 emails in one day
🎯 Send to engaged customers first — your most loyal repeat buyers are more likely to open, which builds your reputation
🧹 Keep your list clean — never email customers who've never opted in, and remove bounces quickly
📊 6. Check your bounce rate
If you're sending to customers with invalid emails, those bounces hurt your reputation. The email activity log shows you which sends bounced — review periodically and clean up your customer list.
💡 Pro Tip
If a single customer complains about spam, it's usually their inbox filter being weird. If many customers complain, it's a real deliverability problem — set up a custom sending domain immediately if you haven't.
🆘 Still stuck?
Reach out and include:
Your sending domain (custom or default)
A few example emails customers say went to spam
The customer's email provider (Gmail, Outlook, etc.)
We can run a deliverability check and recommend next steps.