Cold Email Going to Spam? The Complete Deliverability Checklist for 2026
You've crafted the perfect cold email. You've got a great list. You hit send. And... crickets. Your emails are going straight to spam. Here's how to fix it.
Key Takeaways
- 45% of all email is spam, making inbox placement harder than ever
- Technical setup (SPF, DKIM, DMARC) is non-negotiable
- Email warm-up is essential for new domains
- Content and sending patterns affect deliverability more than you think
Why Your Cold Emails Land in Spam
1. Technical Setup Is Wrong
Email providers check your domain's authentication records:
- SPF - Tells receivers which servers can send for your domain
- DKIM - Digitally signs your emails to prove authenticity
- DMARC - Tells receivers what to do if SPF/DKIM fail
If these aren't configured correctly, you're flagged as suspicious.
2. Domain/IP Reputation Is Bad
Sending from a new domain? Email providers don't trust you yet. Sending from a domain with spam complaints? You're blacklisted.
3. Content Triggers Spam Filters
Words like "FREE!!!", "Act now!", or "Congratulations!" trigger spam filters. So do:
- Too many links
- Large images
- URL shorteners
- Excessive punctuation!!!
4. Bad Sending Patterns
Sending 1,000 emails on day one from a new domain? Straight to spam. Email providers expect gradual volume increases.
The Complete Deliverability Setup
Step 1: Technical Authentication
SPF Record: Add a TXT record to your DNS:
v=spf1 include:_spf.google.com include:sendgrid.net ~all
DKIM: Your email provider gives you a key to add to DNS. It looks like:
google._domainkey.yourdomain.com
DMARC: Add a TXT record:
v=DMARC1; p=none; rua=mailto:dmarc@yourdomain.com
Step 2: Warm Up Your Domain
Never send cold emails from a brand new domain immediately. Warm it up:
| Week | Daily Volume | Activity |
|---|---|---|
| 1 | 10-20 | Send to friends/colleagues who reply |
| 2 | 30-50 | Mix of warm + light cold outreach |
| 3 | 50-100 | Gradual cold email increase |
| 4 | 100-200 | Monitor bounce rates |
| 5+ | 200+ | Scale based on reputation |
Use warm-up tools that automatically send and receive emails to build reputation.
Step 3: Clean Your List
Bad email addresses kill deliverability:
- Hard bounces - Email doesn't exist = reputation damage
- Spam traps - Old emails recycled to catch spammers
- Role addresses - info@, sales@, admin@ = lower engagement
Use email verification tools before sending.
Step 4: Write Deliverable Content
Good:
Hi Sarah,
I noticed Acme Corp recently expanded into the European market. Congrats! We've helped similar companies streamline their cross-border operations.
Would you be open to a 15-minute call to see if we could help?
Best, John
Bad:
🔥 FREE CONSULTATION!!! 🔥
CONGRATULATIONS! You've been selected for an EXCLUSIVE opportunity!!!
Click here NOW: bit.ly/xyz123
Don't miss out!!!
Step 5: Monitor and Adjust
Track these metrics:
| Metric | Healthy Range | Action if Low |
|---|---|---|
| Open rate | 40-60% | Check subject lines, deliverability |
| Reply rate | 5-15% | Improve personalization |
| Bounce rate | Under 2% | Clean your list |
| Spam complaints | Under 0.1% | Improve targeting, add unsubscribe |
How Dewx Handles Deliverability
Dewx integrates with cold email tools like Instantly to help:
- Automatic warm-up - Built-in warm-up network
- List verification - Clean lists before sending
- Sending limits - Respects daily volume limits
- Rotation - Multiple sending accounts for scale
- Analytics - Track deliverability metrics in real-time
FAQ
How long does warm-up take?
2-4 weeks minimum for a new domain. Don't rush it. Sending too fast too soon can permanently damage your reputation.
Should I use my main domain for cold email?
No. Use a separate domain (like outreach.yourcompany.com) to protect your main domain's reputation.
What's a good cold email open rate?
40-60% is good for targeted B2B cold email. Below 30% indicates deliverability or subject line issues.
Conclusion
Cold email deliverability isn't magic; it's mechanics. Get the technical setup right, warm up your domain, write human-sounding content, and monitor your metrics.
Checklist summary:
- SPF, DKIM, DMARC configured
- Domain warmed up (2-4 weeks)
- List verified and cleaned
- Content written for humans, not spam filters
- Sending volume gradual and consistent
- Metrics monitored weekly
Want help with cold email campaigns? Join the Dewx beta and let us handle the technical stuff.