A dedicated IP is a sending address used by one sender alone. A shared IP is used by many senders at once, and for most cold email the choice is already made for you by whichever mailbox platform you send from. This page is the detail page on IP choice referenced from our cold email deliverability guide, which covers the full set of signals that decide where a cold email lands.
Below: the volume thresholds vendors actually publish for recommending a dedicated IP, how IP warm-up works regardless of which type you use, and why domain reputation, not IP choice, matters most for cold outreach sent from real mailboxes.
What is the difference between a dedicated IP and a shared IP for cold email?
A dedicated IP carries one sender's reputation alone, while a shared IP's reputation reflects the combined sending behavior of everyone using it. The practical effect is that a dedicated IP gives you full control over your own standing but also full exposure to your own mistakes, with nobody else's good behavior to average against.
| Dedicated IP | Shared IP | |
|---|---|---|
| Reputation | Yours alone | Shared across every sender on the IP |
| Control | Full, but also full responsibility | None over other senders using it |
| Warm-up needed | Yes, from zero | Usually already warmed by the provider's other traffic |
| Typical cold email setup | Rare; mostly large dedicated ESP accounts | The default on Google Workspace, Microsoft 365, and most cold outreach platforms |
At what sending volume does a dedicated IP make sense for cold email?
Mailgun's own guidance sets the threshold at a minimum of 100,000 messages a month to use a dedicated IP. It states that "there's a certain amount of sending necessary to establish and sustain a solid reputation" since you are the only sender on the IP. Sending too little on a dedicated IP can be as damaging as sending too much, per Mailgun's own help center article. Mailgun recommends a shared IP below that volume, and a pool of multiple dedicated IPs only for senders in the "several million emails per month" range.
If you cannot confirm a published number from the specific platform you are evaluating, say so rather than guessing. Not every provider publishes a threshold, and figures vary by vendor and by how aggressively a sender ramps volume. Mailgun's 100,000-a-month figure is the clearest primary-source number available. Treat anything below that scale for a single sending identity as a case where a shared IP, or more realistically a dedicated sending domain on shared mailbox infrastructure, is the better fit.
How does IP warm-up work, and does it matter for cold email on a shared IP?
IP warm-up is the gradual ramp of sending volume on a new IP address, letting a mailbox provider build evidence that the sender behind it is legitimate before trusting it with full volume. Mailgun's own guidance notes that "new dedicated IPs require warm-up before you send at full volume," since mailbox providers have no history to judge a brand-new IP by.
For a dedicated IP, this warm-up is your responsibility and starts from zero every time. For cold email sent from a mainstream mailbox platform on a shared IP, the IP itself is typically already established. The sending domain and individual mailbox still need their own warm-up, because reputation at the domain and mailbox level is tracked separately from the IP. Our warm-up guide covers how that domain and mailbox-level ramp works for cold outreach specifically.
Why does domain reputation matter more than IP choice for cold email sent from Google Workspace or Microsoft 365?
Because the sending IP on Google Workspace or Microsoft 365 is shared across millions of other mailboxes and entirely outside any individual sender's control, while the sending domain's reputation is isolated and something you can actually manage. Our sender reputation guide covers domain versus IP reputation in full; for cold outreach specifically, domain reputation is the lever that is both available and worth protecting.
This is also why a damaged domain is recoverable in a way a damaged shared IP is not. You can retire a burned sending domain and replace it for a few dollars, but you cannot retire Google's or Microsoft's shared sending infrastructure. Our burned domain recovery guide covers how that replacement works in practice. Our blacklist check guide covers how to tell whether a domain or IP is actually causing a deliverability problem before assuming it is the IP's fault.
Does a dedicated IP help cold email avoid spam filters?
Not reliably, and for most cold outreach senders it can make things worse rather than better, because a dedicated IP with low or inconsistent volume looks suspicious to mailbox providers in exactly the way Mailgun's own guidance describes. A shared IP on established infrastructure like Google Workspace or Microsoft 365 benefits from the overall trust that infrastructure has built, as long as your own sending domain and mailbox stay clean.
The signals that actually move cold email into or out of spam are the ones at the domain and content level: SPF, DKIM and DMARC alignment, bounce rate, spam complaints and sending volume ramp. Our why cold emails go to spam guide covers these in full; IP type is a minor factor next to any of them for a sender using mainstream mailbox infrastructure.
Can a dedicated IP ever hurt cold email deliverability?
Yes, specifically at low or inconsistent volume. Mailgun's own guidance states that sending too few messages on a dedicated IP "can be just as damaging as sending too many messages," because mailbox providers treat an IP with thin, irregular sending history as suspicious rather than trustworthy. A cold outreach program running a modest number of mailboxes rarely generates the consistent volume a dedicated IP needs to build a stable reputation on its own.
How does Pipefire handle sending infrastructure for cold email?
Pipefire sends cold email from real mailboxes it sets up for you, on shared sending infrastructure rather than a dedicated IP, which matches the volume most cold outreach programs actually run at. What Pipefire controls directly is the sending domain: SPF, DKIM and DMARC written for every domain, 14-day warm-up before any domain starts sending, and automatic pause at 3% hard bounces or 0.1% complaints so one mailbox's trouble does not spread.
See our sending domain setup for how domains and mailboxes get created, and our deliverability guide for the full set of signals that matter more than IP type for cold outreach at Standard-plan volume.
Dedicated IP vs shared IP cold email FAQ
Should I use a dedicated IP for cold email?
Usually not. Mailgun's own volume guidance puts the threshold at a minimum of 100,000 messages a month for a dedicated IP to make sense, and most cold outreach programs, run from a handful of mailboxes, send well under that. A shared IP on established mailbox infrastructure is the better fit at typical cold email volume.
Does Google Workspace or Microsoft 365 give me a dedicated IP for cold email?
No, standard Google Workspace and Microsoft 365 plans send on shared IP infrastructure used by many customers. Dedicated IPs on either platform are enterprise-level arrangements well beyond what a cold outreach program needs.
How long does IP warm-up take for cold email?
It depends on the IP and the provider's own ramp schedule, and Mailgun does not publish a fixed number of days. What matters more for most cold email senders is domain and mailbox warm-up, which our warm-up guide covers in detail.
Does a shared IP mean my cold email reputation depends on strangers?
Partly, but less than it sounds. The IP's baseline trust is shared, but your sending domain's reputation, which is what receivers weigh most heavily for cold outreach, is tracked and managed separately from the IP. A clean domain on a shared IP performs very differently from a messy one on the same IP.
Is a dedicated IP worth it for a single cold email sending domain?
Rarely, unless that one domain is sending at the six-figure-a-month volume Mailgun's guidance describes. Below that, the IP will likely sit under-warmed and look more suspicious to mailbox providers than a shared IP with an established history would.