Quick Summary
- Scaled from 100 to 15,000 emails/day in 6 months
- Maintained 95% inbox placement throughout
- Complete infrastructure guide
- Domain setup and warmup strategy
- Cost breakdown at each scale level
Most people can't scale cold email past 500/day without spam folder death.
I scaled from 100 to 15,000 emails per day while maintaining 95% inbox placement.
The Scaling Roadmap
Level 1: 100 emails/day
Infrastructure needed:
- 3 domains
- 3 email accounts
- Basic warmup (14 days)
Cost: $150/month
Level 2: 500 emails/day
Infrastructure needed:
- 10 domains
- 10 email accounts
- Advanced warmup (21 days)
- Dedicated IP
Cost: $380/month
Level 3: 2,000 emails/day
Infrastructure needed:
- 30 domains
- 30 email accounts
- Rotation system
- Multiple IPs
Cost: $890/month
Level 4: 5,000 emails/day
Infrastructure needed:
- 75 domains
- 75 email accounts
- Load balancing
- Dedicated warmup team
Cost: $1,890/month
Level 5: 15,000 emails/day
Infrastructure needed:
- 200+ domains
- 200+ email accounts
- Advanced rotation
- Multiple sending platforms
Cost: $4,200/month
Critical Scaling Rules
Rule 1: Never Send >50 Emails Per Account Per Day
This is the golden rule. Stay under 50/day per account.
Rule 2: Add Domains Gradually
Don't jump from 3 to 30 domains overnight.
Safe scaling: Add 5-10 new domains every 2 weeks.
Rule 3: Warmup EVERY Account
New accounts need 14-21 day warmup before sending cold emails.
Rule 4: Monitor Deliverability Daily
Check inbox placement with tools like GlockApps or MailReach.
If placement drops below 85%: Stop sending, investigate.
Domain Setup Strategy
Primary Domain (Your Brand)
Example: aiagenix.com
Use for: Receiving replies, calendar links, website
NEVER send cold emails from this
Sending Domains (Variations)
Examples:
- get-aiagenix.com
- try-aiagenix.com
- aiagenix.co
- aiagenix.io
- aiagenix-labs.com
Use for: Sending cold emails
DNS Setup (For Each Domain)
- SPF record
- DKIM record
- DMARC record
- Custom tracking domain
For complete DNS setup, see our infrastructure guide.
Warmup Strategy
Week 1: 5 emails/day
- Send to warmup network
- High engagement (opens, replies)
- Build sender reputation
Week 2: 15 emails/day
- Increase volume slowly
- Mix warmup + test emails
- Monitor placement
Week 3: 30 emails/day
- Start real cold emails
- 70% cold, 30% warmup
- Watch bounce rate closely
Week 4+: 50 emails/day (max)
- Full cold email volume
- Maintain daily warmup
- Never exceed 50/day per account
Tools for Scaling
- Instantly: Best for managing 100+ accounts ($97-297/mo)
- Smartlead: Advanced rotation ($94-294/mo)
- Warmbox: Automated warmup ($19/mailbox)
- GlockApps: Deliverability testing ($79/mo)
Cost Breakdown at 15,000/day
- Domains (200): $2,400/year = $200/month
- Google Workspace (200): $1,200/month
- Instantly Pro: $297/month
- Warmup tools: $600/month
- Deliverability monitoring: $79/month
Total: $2,376/month to send 450,000 emails/month
Cost per email: $0.0053
Monitoring & Maintenance
Daily Tasks
- Check inbox placement rate
- Review bounce rates (should be under 3%)
- Monitor reply rates
- Check for blacklisting
Weekly Tasks
- Add new domains to rotation
- Remove underperforming domains
- Update warmup settings
- Analyze campaign performance
Monthly Tasks
- Deep dive deliverability audit
- Renew domains
- Optimize domain rotation
- Scale planning
Red Flags to Watch
Stop sending immediately if:
- Inbox placement drops below 85%
- Bounce rate exceeds 5%
- Domains get blacklisted
- Reply rate drops by 50%+
Common Scaling Mistakes
Mistake 1: Scaling Too Fast
Going from 100 to 5,000/day in one week = spam folder death.
Solution: Scale 20-30% per month max.
Mistake 2: Not Diversifying Platforms
Using only Google Workspace = single point of failure.
Solution: Mix Google + Microsoft + custom SMTP.
Mistake 3: Ignoring Deliverability
Many people scale volume but ignore inbox placement.
Solution: Test deliverability weekly with GlockApps.
For complete deliverability optimization, see our deliverability guide.
— Muhammad
AI Agenix