Short answer
Use a shared IP pool until you send steady volume every day; use a dedicated IP when you send enough, consistently enough, for mailbox providers to judge the IP on your mail alone, or when customers need fixed IPs to allowlist. Below that, a well-run shared pool usually delivers better, because a quiet dedicated IP has no history and receivers treat unknown IPs cautiously.
A dedicated IP isolates your reputation. A dedicated server goes further and isolates the queue, the configuration and the IPs, which matters for security reviews and for senders who can't share anything.
On this page
What shared and dedicated IPs are
Every email leaves a mail server from an IP address. Gmail, Outlook, Yahoo and the rest keep a reputation for that IP, built from what they have seen arrive from it: volume, bounces, spam complaints, spam-trap hits and how recipients engage. They also keep a reputation for your domain, built from the DKIM-signed mail that carries it. Both feed the decision to deliver to the inbox, to the spam folder, or not at all.
On a shared IP pool, your mail leaves from addresses that other senders use too. The IP reputation is the sum of everyone on the pool. On a dedicated IP, only your mail uses the address, so its reputation is built from your sending alone.
| Shared pool | Dedicated IP | Dedicated server | |
|---|---|---|---|
| Who else sends from the IPs | Other customers on the pool | Nobody | Nobody |
| Who else shares the mail server and queue | Other customers | Other customers | Nobody |
| IP reputation comes from | Everyone on the pool | Your mail only | Your mail only |
| Works from the first email | Yes, on an established pool | Needs warmup | Needs warmup |
| Fixed IPs customers can allowlist | No | Yes | Yes |
| Volume it needs | Any | Steady daily volume | Steady daily volume |
Domain reputation travels with your DKIM-signed domain in all three cases.
When a dedicated IP is worth it
- You send steady volume every day. Enough that the IP always has a recent history with Gmail and Outlook. Providers set their own floors, typically somewhere in the tens to hundreds of thousands of emails a month, and the shape of your traffic matters as much as the total: daily and even beats a monthly spike.
- You want your reputation to be yours alone. If you already send clean mail with low complaint rates, a dedicated IP stops you from absorbing anyone else's mistakes.
- Customers need to allowlist your IPs. Enterprise customers and some receiving systems filter by sending IP. You can only give them a fixed list if the IPs are yours.
- You want clean signals for debugging. Postmaster data, blocklist checks and bounce patterns on a dedicated IP describe your mail and nothing else.
Dedicated IP vs dedicated server
The phrase "dedicated IP" covers a lot of ground. At most providers it means your mail leaves from IPs nobody else uses, while still sharing the provider's mail servers, queues and configuration with every other customer. That isolates IP reputation. It doesn't isolate anything else.
A dedicated server is your own mail server with your own IPs. Nobody else's traffic sits in your queue, a spike from another customer can't delay your sign-in codes, and you can answer a security questionnaire's "is our mail processed on shared infrastructure?" with a plain no.
| Need | Dedicated IP | Dedicated server |
|---|---|---|
| Your own IP reputation | Yes | Yes |
| Fixed IPs for allowlists | Yes | Yes |
| Your own queue, unaffected by other senders' spikes | No | Yes |
| No shared mail infrastructure for security reviews | No | Yes |
Groundmail offers both. Dedicated IPs run on our servers with reputation that's yours alone. The Dedicated plan is your own mail server and IPs, built, warmed and managed by us, from $299/mo with 250,000 emails included and $0.80 per 1,000 after that. Because Groundmail runs its own mail servers on its own IP space, both options come from the same team that runs the shared pool.
What dedicated IPs cost and require at other providers
Most providers ration dedicated IPs by plan or volume, because an IP without steady traffic can't hold a reputation. Here is what each one publishes:
| Provider | Dedicated IP price | Who can get one |
|---|---|---|
| Postmark | $50 per IP per month | At least 300,000 messages a month, on Pro plans or higher |
| Resend | $30 per month add-on | Scale plan only, for senders above 3,000 emails a day |
| SendGrid | 1 included on Pro and Premier; extra IPs $30 per IP per month | Pro plan (from $89.95 for 100,000 emails) or higher |
| Mailgun | 1 included on Foundation 100k and Scale; extra IPs $59 per IP per month | Foundation at 100,000 emails a month, or Scale |
| Amazon SES | $24.95 per IP per month (you manage warmup), or managed IPs at $15 per month plus $0.08 per 1,000 | Any account |
| Groundmail | Dedicated IPs: priced with you. Dedicated server: from $299/mo with 250,000 emails | Talk to us; we recommend the option that fits your volume |
Last checked on each vendor's public page.
How warmup works when you move
A new IP has no history, so mailbox providers throttle or filter it until they've seen enough good mail from it. Warmup means sending a small, gradually rising share of your real traffic over the new IP while the rest stays on the old one, and watching bounces, deferrals and complaints as the share grows.
- 1
Fix authentication and list hygiene first
SPF, DKIM and DMARC aligned on your sending domain, bounces suppressed, and no old or purchased addresses. A clean start is most of the work.
- 2
Start with your most-engaged mail
Sign-in codes and password resets get opened quickly. That engagement is the strongest positive signal a new IP can get.
- 3
Raise the share gradually
Move more traffic each day while deferrals and spam-folder placement stay flat. Pause or step back if Gmail or Outlook start deferring.
- 4
Keep it busy
Once warm, keep the IP sending every day. Long gaps cost reputation, which is why low-volume senders are better off shared.
On Groundmail you don't run this schedule yourself: we warm dedicated IPs and dedicated servers with you before traffic moves over, and your code doesn't change because the API and SMTP relay stay the same.
How to decide
| Your situation | Choose |
|---|---|
| Low or uneven volume, clean mail | Shared pool (check what else the pool carries) |
| Steady daily volume, want your own reputation | Dedicated IPs |
| Customers need IPs to allowlist | Dedicated IPs or a dedicated server |
| Security review asks about shared infrastructure | Dedicated server |
| Mail is landing in spam today | Fix authentication and content first, then decide |
Not sure where you fall? Tell us your monthly volume and how it's spread through the week at contact@groundmail.dev and we'll recommend the shared pool, dedicated IPs or a dedicated server.
Frequently asked questions
Is a shared IP bad for deliverability?
No. A well-run shared pool that only carries the same kind of mail as yours often delivers better than a dedicated IP at low volume, because its IPs already have a steady history. The risk with shared IPs is the other senders, so ask what the pool is allowed to carry.
How much volume do I need for a dedicated IP?
Enough to send every day, steadily, so mailbox providers keep seeing your mail on that IP. Providers publish different minimums, and the shape of the traffic matters as much as the monthly total. If your volume is low or bursty, stay on a shared pool.
Do I need to warm up a dedicated IP?
Yes. A new IP has no reputation, so traffic moves over gradually while bounces and deferrals are watched. On Groundmail we warm dedicated IPs and dedicated servers with you before traffic moves.
What's the difference between a dedicated IP and a dedicated server?
A dedicated IP gives your mail its own IP reputation but still runs on shared mail servers and queues. A dedicated server is your own mail server and IPs, so nothing about sending is shared with other customers.
How much does a dedicated server cost on Groundmail?
The Dedicated plan starts at $299/mo with 250,000 emails included and $0.80 per 1,000 after that. It's scoped with our team because capacity depends on your volume. Dedicated IPs on their own are also available; talk to us for a quote.
Will a dedicated IP fix emails going to spam?
Usually not on its own. Spam placement for transactional mail most often comes from authentication gaps, a new or unaligned domain, or content. Fix those first, then decide on isolation.
Sources
Facts on this page about other companies' products, prices and policies come from these public pages. They change, so check them before you decide.