Shared vs dedicated IPs, and warmup
When a dedicated IP helps, when it hurts, and what warming one up actually involves.
In short
- A dedicated IP is only an advantage if you send enough, consistently, to build a reputation on it.
- Below roughly a few thousand messages a day, a shared pool almost always delivers better.
- A new IP starts with no reputation, so it has to be warmed up over two to six weeks.
- Domain reputation follows you across IPs, so changing IP does not reset a bad history.
Shared and dedicated
On a shared IP, your mail leaves alongside other senders’ mail, and the IP’s reputation is the aggregate of everyone using it. Low volume is fine because the pool always carries enough traffic for receivers to have an opinion about it. The trade is that you do not fully control that opinion.
On a dedicated IP, the reputation is entirely yours. Nobody else can damage it, and nobody else helps it either. That second half is the part people underestimate.
Receivers form an opinion of an IP from the volume and quality of mail it sends. An IP sending 200 messages a day generates too little signal to build a strong reputation. It tends to be treated with more suspicion than a busy, well-behaved shared pool. A dedicated IP at low volume is not neutral. It is worse.
| Shared | Dedicated | |
|---|---|---|
| Low volume | Works well | Works poorly |
| Reputation control | Partial | Complete |
| Effect of your own mistakes | Diluted | Concentrated |
| Needs warmup | No | Yes |
| Tolerates irregular sending | Yes | Poorly |
Do you need one?
You want a dedicated IP when you send enough volume to establish reputation on it, that volume is reasonably steady, and you want your sending isolated from other senders’ behavior. As a rough threshold, sustained volume in the thousands per day rather than the hundreds.
You do not want one when your sending is spiky (a few big sends a month), your volume is modest, or nobody will be watching the metrics. In all three cases a shared pool absorbs the variance for you.
A dedicated IP is not a fix for poor deliverability. If your complaint rate is high or your list is dirty, a dedicated IP gives you a private place to accumulate a bad reputation faster. See why your emails go to spam.
What warmup actually is
A new IP has no history, and sending 50,000 messages from it on day one looks exactly like a compromised host. Warmup is the process of establishing a pattern gradually.
The principles matter more than any specific schedule:
- Start small, in the low hundreds per day per provider.
- Increase gradually, roughly doubling every few days as long as the signals stay clean.
- Send to your most engaged recipients first. Early positive engagement is what builds the reputation.
- Watch bounces and complaints at each step, and pause the ramp when either rises rather than pushing through.
- Keep it consistent. A gap of a week early in warmup costs you progress, because reputation decays without traffic.
Two to six weeks is typical to reach full volume, longer for very high volume.
In Mailverick
Dedicated IPs are included based on your sending volume rather than sold as an add-on, and warmup is managed for you. An IP carries a status of warmup, active, or inactive, and while it is warming up, traffic is ramped rather than switched over at once.
Each IP also carries a health score from 0 to 100 derived from delivery outcomes, which is what informs how mail is distributed across the pool. There is nothing to schedule or throttle on your side.
Because the assignment follows volume, you do not have to make the shared-or-dedicated decision yourself: sending too little for a dedicated IP to make sense means you keep the pool that suits that volume.
Common mistakes
Asking for a dedicated IP too early. The most common self-inflicted deliverability problem. Volume first, then dedication.
Warming up with your worst addresses. Some senders start warmup with an old list to “test” it. That teaches receivers that this new IP sends to dead addresses.
Ramping through a warning. Rising complaints during warmup mean stop, not continue more carefully.
Going quiet after warmup. Reputation is maintained by continued sending. Weeks of silence and then a large send undoes the work.
Splitting small volume across several IPs. Each one gets a fraction of the signal, so several weak reputations replace one adequate reputation.
Expecting an IP change to fix a domain problem. Domain reputation is tracked independently and follows the From: domain wherever it sends.
FAQ
Will a dedicated IP improve my delivery?
Only if you have the volume to support it. At sufficient scale it gives you isolation and control. Below that it usually costs you delivery.
How long does warmup take?
Two to six weeks to full volume in most cases, and longer at high volume. It is bounded by receivers observing your behavior over time, which is not something that can be accelerated.
What happens if I stop sending for a while?
Reputation decays. Coming back at your old volume after a long pause reads as a sudden spike from an IP with no recent history, which is exactly what receivers penalize. Ramp back up.
Does changing IP reset a bad reputation?
No. Domain reputation is the more durable of the two and it moves with you. Fix the cause rather than the address.
Can I have several dedicated IPs?
At sufficient volume, yes, and it is how large senders isolate different mail streams. Splitting volume that does not need splitting weakens every IP involved.
Last updated: April 2026