What is Shared IP vs Dedicated IP?
When sending email, your messages originate from an IP address. A shared IP means your emails are sent from the same IP address used by many other senders (managed by your ESP). A dedicated IP means you have your own exclusive IP address that only your emails use.
The choice between shared and dedicated IP directly impacts your deliverability and is one of the most important infrastructure decisions for outbound teams.
Why This Matters for Outbound
On a shared IP, your reputation is partially determined by the behavior of other senders sharing that IP. If another sender on your shared IP starts spamming, your deliverability suffers too. On a dedicated IP, your reputation is entirely in your hands, but you also need enough volume to build and maintain that reputation.
Key Considerations
- Shared IP Pros: No warmup needed, reputation pooled across senders, good for low-volume senders
- Shared IP Cons: Other senders' behavior affects you, less control, potential blacklisting from others' actions
- Dedicated IP Pros: Full reputation control, isolation from bad actors, better for high-volume sending
- Dedicated IP Cons: Requires warmup, needs consistent volume (50K+/month), your mistakes only affect you
Volume Thresholds
- Under 10,000 emails/month: Shared IP is usually better
- 10,000-50,000 emails/month: Either can work; test both
- Over 50,000 emails/month: Dedicated IP is strongly recommended
Common Mistakes
- Getting a dedicated IP without enough volume: Low-volume dedicated IPs never build sufficient reputation
- Not warming up a new dedicated IP: Sending full volume on day one will get you blacklisted
- Assuming shared IP is always bad: High-quality ESPs actively manage shared IP reputation
- Ignoring IP reputation monitoring: Whether shared or dedicated, monitor your IP reputation regularly
How FlowStrata Approaches IP Strategy
FlowStrata evaluates each client's sending volume, frequency, and growth plans to recommend the optimal IP strategy. For high-volume clients, we provision dedicated IPs with structured warmup plans. For lower-volume engagements, we use vetted shared IP pools with established positive reputations, ensuring no client's deliverability is compromised by external factors.