The dedicated IP vs shared IP choice comes down to whose reputation you send under. A shared IP address is used by many customers of the same provider, so its reputation is built by all of them together. A dedicated IP address is yours alone, so its reputation reflects only your own sending. A dedicated IP gives you control and isolation, but it needs steady volume, clean lists and a proper warm-up. This guide helps you decide which you need and how to run it well.
A dedicated IP is not a shortcut. It does not fix poor list quality or missing authentication. It makes your own sending habits the only thing that counts, for better or worse.
The short version
- Low or irregular volume. Stay on shared IPs. They already carry steady traffic and a managed reputation.
- Large, steady volume. A dedicated IP gives you control and a reputation that is yours.
- Mixed mail types at scale. Use separate IPs, or pools, for transactional and marketing mail.
- Whatever you choose. Authenticate with your own domain, keep lists clean and watch the numbers.
Dedicated vs shared at a glance
| Shared IP | Dedicated IP | |
|---|---|---|
| Reputation | Shared with other customers and managed by the provider | Yours alone |
| Control | Limited. Others affect the pool | Full. Your habits decide the outcome |
| Warm-up | Not needed for the IP, still needed for a new domain | Required, takes several weeks |
| Best for | Low or irregular volume, new senders, small teams | High, steady volume and strict isolation needs |
| Main risk | Another sender damages the IP | Too little traffic to build reputation, or your own mistakes |
| Cost | Included in most plans | Extra monthly cost per IP |
| Isolation of mail types | No | Yes, with separate IPs or pools |
When a shared IP is the better choice
- You send fewer than tens of thousands of messages a month. A dedicated IP would see too little traffic to build a reputation receivers can judge.
- Your volume is bursty. Long gaps let a dedicated IP go cold, and big spikes look suspicious.
- You are new to email. A well-run shared pool lets you start sending without a warm-up on the IP itself.
- You do not have time to monitor. A dedicated IP rewards attention and punishes neglect.
When a dedicated IP makes sense
- Steady high volume. You send most days, in the range of 100,000 or more messages a month, with a stable pattern.
- You need isolation. Your transactional mail must never suffer for marketing complaints, or the other way round.
- You want control. You want your reputation to depend only on your own list quality and habits.
- You have a track record. Bounces are low, complaints are low and authentication is complete.
- Compliance or customer requirements. Some customers or contracts ask for a fixed sending IP they can allow-list.
A decision table
| Your situation | Recommended setup |
|---|---|
| Under 50,000 messages a month, irregular | Shared IP, authenticated with your own domain |
| 50,000 to 100,000 a month, steady | Shared IP, or one dedicated IP if you need isolation |
| 100,000 to 1,000,000 a month, steady | One dedicated IP for marketing, shared or a second IP for transactional |
| Over 1,000,000 a month | Several dedicated IPs in pools by mail type and region |
| Mostly transactional, high engagement | Dedicated IP is optional. Protect it from marketing traffic |
| Recently damaged reputation | Fix the cause first. A new IP will not hide it |
These are starting points. Volume bands are rules of thumb, not provider requirements. Consistency and quality matter more than the raw number.
Set up a dedicated IP
- Get the IP. Request a dedicated address from your provider and note its reverse DNS name.
- Set reverse DNS. The IP should resolve to a host name that resolves back to the same IP. Receivers check this.
- Update SPF. Add the new IP, or confirm your SPF record already covers it through your provider include.
- Keep DKIM and DMARC. Authenticate with your own domain so reputation follows the domain and not only the IP.
- Split traffic. Decide which streams use which IP. Keep transactional mail separate from marketing mail when you can.
- Warm it up. Follow a staged plan, starting with your most engaged recipients.
Warm up a dedicated IP
A new IP has no history, so mailbox providers treat its first messages carefully. You build trust by sending a little at first, to people who want your mail, then raising volume in steps. The full day-by-day plan is in the email warm-up guide. A summary:
| Week | Daily volume | Audience |
|---|---|---|
| 1 | 50 to 500 | Most engaged recipients, opened in the last 30 days |
| 2 | 500 to 2,500 | Engaged in the last 60 days |
| 3 | 2,500 to 10,000 | Engaged in the last 90 days |
| 4 | 10,000 to 25,000 | Broader active list |
| 5 to 8 | Raise towards your normal volume | Full list, with the least engaged last |
Slow down at the first warning. If bounces rise above 2 percent, complaints pass 0.10 percent or you see many 4xx deferrals, hold volume where it is, or step back, until the numbers settle.
Plan your IP pools
| Pool | Contains | Why |
|---|---|---|
| Transactional | Password resets, receipts, alerts | High engagement and time sensitivity. Protect it from marketing complaints |
| Marketing | Newsletters and promotions | Lower engagement and more complaints. Keeps risk away from critical mail |
| Re-engagement or risky | Older or lower-quality segments | Contains the damage if something goes wrong |
| Shared overflow | Small or irregular streams | Uses the provider reputation when you do not have the volume |
Monitor the IP and the domain
- Google Postmaster Tools: check spam rate, authentication and delivery errors for your domain.
- Microsoft sender support: review how Outlook.com treats the IP and ask for help when it blocks you.
- Blocklist checks: look up the IP regularly on the major lists. A new IP can inherit a previous owner listing, so check before you start.
- Delivery logs: watch deferrals, bounces and complaints by provider. See the bounce code guide.
- Cadence: send regularly. Long gaps cool the IP.
Common mistakes
| Mistake | Result | Fix |
|---|---|---|
| Moving to a dedicated IP at low volume | Too little traffic to build a reputation | Stay on shared IPs until volume is steady |
| Skipping the warm-up | Throttling, spam placement, blocks | Follow a staged plan |
| Sending your whole list on day one | Spike looks like abuse | Start with engaged recipients |
| One IP for every kind of mail | Marketing complaints hurt receipts | Separate transactional and marketing |
| Ignoring the domain | Reputation resets when the IP changes | Authenticate and build domain reputation |
| Not checking the IP history | Inherited blocklist listing | Look up the IP before the first send |
Not sure which setup fits? Tell us your monthly volume and the kinds of mail you send and we will suggest a setup.
Further reading and sources
Frequently asked questions
What is the difference between a dedicated and a shared IP?
A shared IP address is used by several senders at the same provider, so its reputation reflects all of them. A dedicated IP address is assigned to a single customer, so its reputation depends only on that customer sending behaviour. A dedicated IP gives control and isolation but needs steady volume and a warm-up.
Do I need a dedicated IP?
Not necessarily. Many senders do well on well-managed shared IPs. A dedicated IP makes sense when you send large volumes on a steady schedule, need to separate your reputation from other senders, or need to isolate transactional from marketing mail. Low or irregular volume usually does better on shared IPs.
How much volume do I need for a dedicated IP?
There is no fixed rule. Providers often suggest considering a dedicated IP once you send steadily in the range of 100,000 or more messages a month, and it helps if you send most days. Below that, a dedicated IP may see too little traffic to build a clear reputation.
Does a dedicated IP improve deliverability by itself?
No. A dedicated IP gives you control, which is good only if your list quality, authentication and sending habits are good. A poor sender on a dedicated IP simply builds a poor reputation faster, with nobody else to share it.
How long does it take to warm up a dedicated IP?
Plan for about four to eight weeks to reach full volume, or around 30 days for moderate volume. Start with your most engaged recipients and increase gradually. The warm-up guide has a day-by-day plan.
Is domain reputation or IP reputation more important?
Both matter, and large providers such as Gmail weigh the sending domain heavily. A good domain can partly protect you when the IP changes, and a bad domain follows you across IPs. Authenticate with your own domain so your reputation travels with you.
What are the risks of a shared IP?
Another sender on the same IP can damage its reputation. A good provider limits this by screening new customers, monitoring complaints and moving problem senders away. Ask your provider how it manages shared pools.
What is an IP pool?
An IP pool is a group of IP addresses that you send from together. You can split traffic across pools, for example one for transactional mail and one for marketing, so a problem with one type of mail does not affect the other. Pools also share load for large volumes.
Should transactional and marketing mail use different IPs?
If you have enough volume for both, yes. Password resets and receipts have high engagement and should not be dragged down by marketing complaints. If you only have enough volume for one dedicated IP, use separate subdomains and keep marketing volume modest.
What happens if I stop sending on a dedicated IP?
Reputation fades when an IP goes quiet. After a long gap, treat the IP as partly cold: resume at a reduced volume and ramp up again in steps instead of sending a large campaign at once.