The Core Difference#
Your sending IP address is how receiving mail servers identify you. Its reputation — built from your sending history — directly affects whether your emails land in the inbox or spam folder.
|
Dedicated IP |
Shared IP |
| Reputation |
Yours alone |
Shared with other senders |
| Warmup required |
Yes (4–8 weeks) |
No |
| Cost |
Higher |
Lower or free |
| Control |
Full |
None |
| Risk |
Low (if done right) |
Medium (others can harm you) |
| Best for |
50K+ emails/month |
Low-volume senders |
When to Use a Dedicated IP#
- You send more than 50,000 emails per month consistently.
- You need full control over your sending reputation.
- You have the time and volume for a proper IP warmup.
When a Shared IP Is Fine#
- You send fewer than 50K emails/month.
- You use a reputable ESP (Amazon SES, SendGrid) whose shared IP pools are well-managed.
- You are just starting out and do not have warmup volume.
IP Warmup Summary#
A new dedicated IP has no reputation. ISPs are suspicious of unknown IPs. To build trust:
- Week 1: Send to your most engaged subscribers only — 200–500/day.
- Week 2–3: Double volume every few days.
- Week 4–6: Reach your target volume gradually.
Monitor bounce rate, spam complaints, and Gmail Postmaster Tools during warmup. Any spike above 0.1% complaint rate means slow down immediately.
