Most Klaviyo guides about IP warming contain advice that doesn’t apply to the sender reading it. That’s because the majority of Klaviyo accounts are not on dedicated IPs and never will be.
What applies to almost every Klaviyo sender is domain warming, and that’s a different process with a different timeline and different rules. The confusion between the two is one of the most common reasons eCommerce senders mismanage their early sending periods, either skipping warming entirely because they think it doesn’t apply to them, or following a dedicated IP schedule when they’re actually on shared infrastructure.
There’s also a more important point that most warm-up guides miss entirely: mailbox providers now weight domain reputation more heavily than IP reputation. That means domain warming is not just relevant to dedicated IP senders. It applies to every Klaviyo sender who sets up a custom sending domain, regardless of which IP infrastructure they’re on.
This post covers both processes accurately, based on Klaviyo’s official documentation, so you know exactly what applies to your setup.
First: Shared IP vs. Dedicated IP
Before getting into warming, it’s worth being clear on which infrastructure you’re actually on.
Klaviyo automatically assigns shared IP addresses to most new accounts. A shared IP means your account sends alongside other Klaviyo customers through the same pool of IP addresses. Your individual sending reputation is tied to your sending domain, not the IP, and Klaviyo actively monitors its shared IP pools, removing senders whose behaviour could harm pool reputation.
A dedicated IP is a single IP address used exclusively by your account. Your IP reputation is entirely your own. This is the right setup for high-volume senders who send at regular frequency, have a clean engaged list, and are not currently dealing with deliverability problems. Klaviyo doesn’t publish a specific volume threshold for dedicated IPs. Eligibility is determined in conversation with your Klaviyo Customer Success Manager.
The practical implication: if you’re on shared IPs, you don’t need to run a formal IP warm-up. What you do need is domain warming when you set up a custom sending domain, and volume ramping if you’re new to Klaviyo or returning after a gap.
What Warming and Ramping Actually Mean
Klaviyo defines these two terms precisely, and the distinction matters.
Warming is establishing reputation with mailbox providers for something that is new or cold: a new dedicated IP, or a new sending domain that has been registered within the last 30 days or has never been used to send email before.
Ramping is gradually increasing your sending volume to introduce a change in infrastructure to mailbox providers. Ramping is part of warming, but it also applies outside of warming: when you’re new to Klaviyo with no sending history, when you’re coming back after a long gap, when you’re preparing for a high-volume period like Black Friday, or when you’re repairing a damaged sender reputation.
Most Klaviyo guides use “IP warm-up” as a catch-all term for both. In practice, what most eCommerce senders are doing, or should be doing, is domain warming combined with volume ramping, not dedicated IP warming.
Domain Warming: What the Schedule Actually Looks Like
When you set up a custom sending domain in Klaviyo for the first time, that domain has no sending history with Gmail, Yahoo, Outlook, or any other mailbox provider. They have no basis for trusting it. Domain warming is the process of building that trust by starting with your most engaged subscribers and expanding gradually as you demonstrate consistent positive engagement signals.
Klaviyo’s domain warming schedule is based on engagement segments, not arbitrary calendar days. Here’s what it looks like:
Weeks 1-2: 30-day engaged segment
Send to subscribers who clicked in the last 30 days, or who subscribed within the last 15 days. Keep each campaign under 10,000 recipients. Target open rates above 30%. You can send daily if needed, but every send at this stage needs to perform well. This is not the time for broad promotional campaigns.
Weeks 3-4: 60-day engaged segment
Expand to subscribers who engaged within the last 60 days. Send up to three times per week. Maintain open rates above 20%. The list size increase should be gradual, not a sudden jump.
Weeks 5-8: 90-day engaged segment
Expand to 90-day engagement window. Send up to twice per week. Continue to target above 20% open rate.
Ongoing: 120-day and 180-day segments
Weekly sends to 120-day engaged subscribers, then monthly sends to 180-day subscribers as the final expansion stage. Only move to each new segment after consistent performance at the previous one.
The critical rule: if your open rate drops below 20% at any stage, stop expanding. Continue sending to the current engagement segment until performance recovers before widening your audience. Trying to push through with volume when open rates are declining is how domain reputation damage happens.
One important note on open rates during warming: Apple Mail Privacy Protection inflates open rates by pre-loading tracking pixels, so your Klaviyo open rate numbers are likely higher than genuine engagement. Klaviyo’s own guidance recommends using click rate as the more reliable engagement signal during warming, since clicks are harder to machine-generate.
Dedicated IP Warming: How Klaviyo Handles It
If you are on a dedicated IP, Klaviyo’s backend manages the routing automatically. When warming begins, Klaviyo sends a small portion of your email volume through the dedicated IP while routing the rest through shared IPs. Over 30-40 days, the proportion sent through the dedicated IP increases progressively. The ramp is non-linear: most of the volume increase happens toward the end of the period, not the beginning. When 100% of your expected volume is routing through the dedicated IP, warming is complete and the IP status changes from “Warming” to “Active.”
You don’t manually control the routing split. What you do control, and what determines whether the warm-up succeeds, is the quality of what you send during that window.
What to send during dedicated IP warming:
Weeks 1-2: Campaigns only. No flows. The reason Klaviyo is specific about this is that flows like abandoned cart and browse abandonment are triggered by behaviour rather than explicit opt-in action. When your dedicated IP volume is low and reputation is being established, a high complaint rate from a flow triggered by a cold browse abandonment segment can damage a reputation that isn’t yet established enough to absorb it. Klaviyo flags this specifically as a risk.
After week 2: You can activate your welcome series and other high-engagement flows. Welcome flows typically generate strong engagement signals and are low complaint risk, making them appropriate to introduce at this stage.
After 30 days: High-risk flows including re-engagement, winback, and sunset sequences can be introduced. These audiences are cold or lapsed by definition, and they carry higher complaint risk. Introducing them before your dedicated IP reputation is established is one of the more common ways warm-ups fail.
Throughout the period, Klaviyo also recommends pausing third-party affiliate marketing, cleaning your list to remove unengaged profiles, and reviewing any underperforming templates before warming begins.
The Thing Most Warm-Up Guides Don’t Tell You
Mailbox providers now weight domain reputation more heavily than IP reputation in their filtering decisions. Klaviyo’s own documentation states this directly: “Inbox providers pay much closer attention to the sending domain reputation versus the sender IP reputation.”
This has a significant practical implication. A sender who is meticulous about their dedicated IP warm-up but neglects their sending domain setup, or who switches to a new custom sending domain without warming it, can still see inbox placement problems despite a fully warmed IP.
It also means that shared IP senders, who have historically been told IP warming doesn’t apply to them, still need to take domain warming seriously. The IP may be warm because other senders are using it, but the domain is new. Gmail, Yahoo, and Outlook are evaluating the domain, not just the IP.
How Inbox Placement Monitoring Fits In
Warming periods are precisely when inbox placement monitoring matters most. During the first 30-40 days of warming, your placement results are volatile. A single campaign that generates elevated complaints can set back weeks of progress. Catching a placement problem on campaign three is far less costly than discovering it on campaign fifteen.
InboxEagle shows you the placement result for every campaign across Gmail, Yahoo, and AOL alongside the authentication results, sending domain, and IP used for that send. During warming specifically, the per-campaign view tells you whether each send is landing in the inbox at the providers you care about, or whether something is going wrong before the pattern compounds.
The DMARC and authentication results in the same view matter during warming too. If your custom sending domain authentication isn’t fully configured before you start warming, authentication failures during the warm-up period can permanently undermine a domain reputation that’s being built from scratch.
What Happens After Warming
Two things trip senders up after warming completes.
The first is treating warming as a one-time event. A fully warmed dedicated IP still needs consistent sending volume to maintain its reputation. According to Klaviyo, dedicated IPs require weekly or more frequent sending to stay active. An IP that goes cold, meaning no significant volume for 30 or more days, effectively needs to be re-warmed. The same applies to domain reputation. A long sending gap followed by a sudden volume spike looks like suspicious behaviour to mailbox providers, regardless of how well the original warm-up went.
The second is assuming good inbox placement after warming is permanent. It isn’t. Deliverability performance can fluctuate for up to 120 days after warming as mailbox providers continue to validate your reputation. Complaint rate, list quality, and engagement signals are evaluated continuously on every send. A single campaign sent to a stale or low-quality segment after warming completes can set back a reputation that took 40 days to build.
The habits that get you through warming successfully, sending to engaged segments, monitoring click rates, suppressing unengaged contacts, checking authentication on every send, are the same habits that protect your inbox placement for every campaign after it. For monitoring your Klaviyo inbox placement on an ongoing basis, the signals to watch are provider-level placement rates, complaint rate trends via Google Postmaster Tools, and authentication pass rates per campaign.
Note: Content created with the help of AI and human-edited and fact-checked to avoid AI hallucinations.
