You do not need a dedicated IP to start sending cold email. A dedicated IP pays off once you send similar volume every working day and someone on your side owns the reputation it builds. Until then, a shared IP from a provider that polices its pool is usually the safer bet.
An IP address identifies the server your email leaves from. On a shared IP, several senders go out through the same address, and receiving servers see their traffic together. On a dedicated IP, the address is yours alone. Every bounce and every complaint lands on your record and nobody else's.
Both options have a catch, and most founders only see one of them. Google notes that the sending quota on an IP is shared by every sender using it, and it tells anyone on a shared IP to check that address's reputation in Postmaster Tools and make sure it is not on a blocklist (Gmail's sender guidelines).
A dedicated IP removes the neighbors, and with them the cover their traffic gave you. A new one has no history. Amazon's SES developer guide states that email providers are less likely to accept mail from new IP addresses with little or no history.
One thing first: if your mailboxes run on Google Workspace or Microsoft 365, there is no IP to choose, because mail leaves from their servers and your domains carry most of the reputation. The IP question starts when you send through your own servers or an infrastructure provider that offers private IPs. For that case, the short rule: stay shared while your volume is small or uneven. Move to dedicated IPs when the volume is steady and one stream of email has to be kept apart from another.
How much sending volume justifies a dedicated IP?
Gmail and Outlook publish rules for bulk senders, but no volume number for when you need your own IP.
The closest reference points come from email platforms. ClickDimensions puts every customer on shared IPs by default. It keeps dedicated IPs for customers who send at least 200K emails a week on a steady schedule, and it calls one large monthly send a poor fit (at the time of writing, ClickDimensions on dedicated IPs).
Rhythm matters as much as size. An IP that sends 400 emails on a Monday, goes quiet for nine days and then spikes gives receiving servers almost nothing steady to judge.
Serious cold email volume is also spread thin on purpose. In our setups, 30 to 35 booked sales calls a month need at least 10,000 people contacted in that same month. That volume goes out across 20 to 40 mailboxes on 10 to 20 domains, so no single account carries much.
One SaaS client in the UAE ran about 1,250 emails a day across 50 email accounts and booked 684 demos in 4 months. Even that load works out to about 25 emails per account a day.
Split across 20 to 40 mailboxes, that is only a few hundred emails per mailbox a month. Even added up across the mailboxes on one IP, that stays far below the weekly volumes email platforms set for their own dedicated IPs, so size will never earn the reputation. Rhythm has to. That is why I give each campaign its own IPs and make sure every one of them sends every working day.
A dedicated IP asks for more than that. Amazon's SES guide on IP warm-up says warming one takes about 2 to 6 weeks, depending on the email provider. After warm-up, it advises sending around 1,000 emails a day to each provider you want to keep a positive reputation with.
When does a dedicated IP help cold outreach, and when does it hurt?
It helps when your sending is predictable. Receiving servers form a view of an IP from what arrives from it, day after day. When the same kind of verified prospects get similar volume every working day, that record grows and stays readable. If placement dips, you know to look at your own lists and pacing first, because nobody else shares the address.
It helps with separation as well. When one brand or one client has a bad month, the complaints stay on that stream's IPs and do not spill into everything else you send.
It hurts when traffic is thin or irregular. Google lists a poorly rated sending IP among the reasons Gmail may temporarily rate limit or block mail (Gmail SMTP errors). On a shared IP, the pool's history softens your first weeks. On a fresh dedicated IP, nothing does.
It also hurts when your lists are rough. Nothing else on the address dilutes your bounces, so a bad list shows up faster and louder. Copy cannot fix a bad list or a weak sender, and neither can a new IP.
Which cold email setup fits your volume and risk level?
| Your situation | Setup | Why |
|---|---|---|
| Still testing the offer; volume changes week to week | Shared IP from a provider that polices its pool | Too little steady traffic to earn a reputation of your own |
| Similar volume every working day, verified lists, one person owns deliverability | Dedicated IPs | The record reflects only your sending, so problems are traceable |
| Several brands or clients sending in parallel | Separate dedicated IPs for each stream | A bad week in one stream stays out of the others |
| Thin volume, but you want to split it "to be safe" | Keep one stream until each IP would get daily traffic | Every extra address divides the traffic each one needs |
| Weak replies, and nobody has checked the list or sender setup | Fix those first, before touching the IP | A new IP carries the same problem to a new address |
Most founders belong in the first row, even when they believe they sit in the second. If the offer and the audience still change every few weeks, keep the infrastructure boring. My rule: pick one offer and one audience and commit to them for 12 months. Infrastructure comes after that decision. Getting the offer itself right usually moves results more than any IP decision.
How many sending IPs do you need for cold email?
Count the reputations you need to keep apart before you count addresses.
For client work, my team gives every campaign its own dedicated sending IPs, and different domains never share an address either. One client can end up sending from 10 to 20 IPs, which is not overkill once you count the domains and mailboxes around it.
To set your own count:
- List the streams that must not share a fate: each brand, each product, and each client if you send for others.
- Give each stream its own sending domains, with dedicated IPs behind them.
- Check that every IP will carry traffic every working day. If one would sit idle half the week, merge it with another.
- Add IPs only when you add accounts to a channel that already books meetings.
More addresses will not save a weak campaign. If you are planning the next step up in volume, that is a question about how to scale cold email.
How do you warm up a dedicated IP before raising volume?
Before any warm-up, the address has to meet Gmail's sender rules, shared IP or dedicated (at the time of writing). Some apply to everyone, some only to bulk senders:
- Gmail's bulk-sender rules start at 5,000 or more messages a day to personal Gmail addresses (Gmail's bulk sender guidance).
- Bulk senders need SPF, DKIM and DMARC, and the From domain has to align with the domain that passes SPF or the one that signs DKIM (Gmail's sender guidelines).
- Mail has to travel over a TLS connection. Marketing and promotional messages need one-click unsubscribe set up with List-Unsubscribe headers, and a mailto or a link in the body is not enough (Gmail's sender guidelines).
- The sending IP needs a PTR record, which is a reverse DNS entry that maps the IP back to a hostname, and that hostname has to resolve back to the same IP (Gmail SMTP errors).
Many B2B prospects sit on Microsoft 365 or Outlook, and Microsoft draws a similar line. Microsoft's post on Outlook's new requirements says they target senders of 5,000 or more messages a day. dmarcian reports that from May 5, 2025, Outlook rejects non-compliant mail from those senders: SPF and DKIM have to pass, and DMARC has to be at least p=none with alignment.
My team sets up SPF, DKIM and DMARC before the first message goes out, even far below the bulk line.
Then keep two kinds of warm-up apart. Mailbox warm-up gets each new email account used to sending and receiving before it touches a prospect, and I want 10 to 14 days of it per account. IP warm-up is about the address itself. A new IP has no record, so it needs real traffic added in steps. Finishing one does not finish the other.
For the address, Google's advice is to raise sending volume slowly to avoid rate limiting (Gmail's sender guidelines). ClickDimensions plans 4 to 6 weeks of IP warm-up on its own platform, starting low and letting volume double each week (at the time of writing, ClickDimensions on dedicated IPs).
A ramp that suits cold email:
- Confirm that authentication and reverse DNS pass on a test send before any prospect gets a message.
- Start with your freshest verified segment and hold older data back until the address has a few clean weeks behind it.
- Send on the same days at similar volume. Gaps erase the pattern you are trying to show.
- Raise volume only after a clean step: no rate-limit errors, bounces inside your limit, no complaint spike.
- If a step comes back with errors, drop to the previous level and hold there.
Running the full campaign at a slower pace is not warm-up. Warm the accounts and the address first, then raise volume.
What should you monitor on a dedicated IP every week?
Opens and replies tell you about the copy. They say little about the IP, because deferrals and rate limits can show up in your sending logs before replies visibly drop. Check these weekly, next to your usual sender reputation check:
- Bounce rate. Mine has to stay below 0.5%, which means verifying every address with NeverBounce or DeBounce before it gets a message.
- Spam rate. Google's target is a Postmaster Tools spam rate under 0.1%, and it should never reach 0.3% (at the time of writing, Gmail's sender guidelines).
- Deferrals and rate-limit errors in your sending logs. A run of temporary failures is often the first visible sign that the IP's standing is slipping.
- Error code 4.7.23, which Gmail returns when the sending IP has no PTR record or its forward lookup does not match the IP (Gmail SMTP errors).
- SPF, DKIM and DMARC results after any change to DNS or to your sending tools.
When a number crosses its line, cut volume on that IP, find the segment that caused it, and clean that list before you ramp back up.
Placement drops and replies thin out, so the copy gets blamed and rewritten while the real cause sits in the sending logs.
The test before you pay: will this IP get the same verified traffic every working day for the next three months? If yes, it can earn its own reputation. If not, a shared pool is doing you a favor.
Deciding between shared and dedicated IPs for your cold email? Book a call and tell me your daily volume, and I will help you work out whether it is worth the change.
Questions about dedicated IPs for cold email
Does Gmail count the bulk-sender line per IP or per domain?
Per domain. Gmail adds up all messages sent from the same primary domain when it decides whether you are a bulk sender (Gmail's bulk sender guidance). Spreading one domain's mail across more IPs does not keep you under the line, so plan authentication and unsubscribe handling as if you will cross it.
Should invoices and support email share an IP with cold email?
No. Google's sender guidelines advise using a different IP address for each type of message when you send more than one type (Gmail's sender guidelines). Cold outreach should also go out from separate domains, so invoices, contracts and support replies from your main address never carry the risk that comes with cold volume.
If a dedicated IP's reputation drops, should I switch to a new one?
Usually not. A new IP starts with no record and has to go through the whole ramp again. Whatever hurt the first address, most often a list or a sending pattern, travels with you to the next one. Cut volume, find and fix the cause, then rebuild on the same IP.
Does a dedicated IP change the legal rules for cold email?
No. The IP only affects how receiving servers judge your mail; the law cares about who you write to and on what basis. Most of our campaigns target the USA, the UK and Europe, in English. Where the rules are stricter, as in Czechia, Germany and Austria, cold email waits for a compliant basis and LinkedIn does the outreach. In the UK and EU, much of that turns on legitimate interest.