How to warm up a new sending domain in Klaviyo

This is for Shopify founders switching to a branded sending domain in Klaviyo, often right before BFCM, who don't want their biggest weeks of the year to land in spam.

What is domain warming in Klaviyo?

By default, Klaviyo says most accounts start sending from a shared IP and a shared Klaviyo domain. A branded sending domain (Klaviyo also calls it a dedicated sending domain) makes your emails come from your brand, which lets inbox providers verify who you are. It also removes the "via klaviyomail.com" label.

The catch is that a new domain has no reputation yet. Warming builds one. Klaviyo describes it as building an initial sender reputation by focusing on your most engaged customers while you slowly increase volume. Klaviyo also says your first sends from a new domain have an outsized effect on that reputation, so go slow.

Gmail says the same thing in its own words: "Start with a low sending volume to engaged users, and slowly increase the volume over time." And it warns against sudden volume spikes if you don't have a history of sending large volumes.

If you haven't set up the domain yet, start with SPF, DKIM and DMARC. Gmail requires all three for bulk senders, and Yahoo asks for a DMARC policy of at least p=none. My Klaviyo DMARC setup guide walks through it, and Gmail, Yahoo and Outlook sender requirements covers the rest of the rules.

Do I need to warm my domain at all?

Not always. Here's how Klaviyo splits it:

• You're already on Klaviyo and moving to a branded domain. No manual warming is needed if the domain was registered at least 30 days ago and has already been used to send email.
• You're replacing one branded domain with another. If the activation screen offers "Move traffic with domain warming," pick it. Klaviyo shifts traffic over gradually. It says "Move all traffic now" can harm deliverability.
• The domain is brand new or has never sent email. Use the standard warming process, as long as you have historical open or click data.
• You have no engagement data. If you're coming from another platform and only have date fields like "last opened," Klaviyo says to use its platform introduction process instead.

Warming applies to marketing domains. Klaviyo says transactional and service domains, which carry order confirmations and password resets, usually don't need it.

Don't mix this up with a dedicated IP. That's a separate setup Klaviyo uses for some managed accounts, and Klaviyo says IP warming typically takes 30 to 40 days.

What is Klaviyo's warm-up schedule?

This is Klaviyo's standard process, not a schedule of my own. It moves by engagement window, not by a fixed daily number:

A few rules from Klaviyo that sit on top of the table:

• Keep your first campaign under 10,000 recipients. Klaviyo says to aim for open rates above 30% on that first send if you can.
• If open rates dip below 20%, stop widening. Stay on your current segment, or tighten it.
• Don't send to inactive subscribers. Klaviyo warns this risks inbox providers moving you to spam.
• Watch the warning. If Klaviyo shows a warming volume warning on a campaign, lower the recipient count to what it recommends.

If your account qualifies, Klaviyo's guided warming helps you pick the audience for each stage and can exclude unengaged people from an oversized send. It times out after 45 days without an email campaign delivered to at least 1,000 people, and once it times out you can't turn it back on.

If you're on the platform introduction process, Klaviyo gives hard numbers instead. A once-a-week sender starts at 2,000 people in week one then goes to 4,000, then 8,000, working up to 65,000 by week eight. Check the article in the sources for your send frequency.

How do I build the warming segments?

Klaviyo's windows are a good frame. Inside each window, I'd rank people the same way I do when I restart email marketing after a break, because a cold domain and a cold list have the same problem: you need the people most likely to engage to go first.

The order I use:

1. People who opened with Apple Mail Privacy Protection disabled. Their opens are real.
2. Consistent clickers.
3. Regular openers.
4. Over a month or two, the 60 and 90-day openers, then all-time openers.

As you go, compare the open and click rates of the bigger, newer segments against the smaller ones you started with. If the new group drags the numbers down, you widened too fast.

Why lean on clicks? Klaviyo itself says Apple Mail Privacy Protection inflates open rates. Across 2,897 campaigns from four consumable brands, Apple auto-opens pushed some segments past 85% open rate, and click rate tracked revenue far better than open rate did (a 0.65 correlation vs 0.32). So a segment can sail past Klaviyo's 20% open rate bar and still be full of people who never read a thing. Check clicks before you widen. More on that in open rate vs click rate.

When should I turn my flows on during warming?

Klaviyo says to only turn on flows that have historically performed well, like welcome, abandoned cart and browse abandonment. For flows that haven't performed well, Klaviyo's timing is:

• Welcome series: after 2 weeks of sending campaigns from Klaviyo.
• Abandoned cart: after 30 days.
• Browse abandonment: after 30 to 60 days.

Klaviyo calls winback, re-engagement and sunset flows high risk, since they usually see low engagement anyway. Hold them until warming is fully done. That includes your Klaviyo sunset flow. It's the right flow at the wrong time here.

For the flows that are on, Klaviyo's bar is open rates above 40%, click rates above 1%, and unsubscribe and complaint rates below 0.1%.

Should Smart Sending be on while I warm up?

For normal campaigns, I keep Smart Sending on. It skips anyone who got an email too recently, which helps keep volume steady.

I turn it off on automations so nobody misses a critical reminder, and on restocks, deadlines, launches and multi-send BFCM days. The full breakdown is in Klaviyo Smart Sending.

Can I switch domains right before Black Friday?

You can, but the timing has to work. Klaviyo says new accounts should warm in the first 2 to 4 weeks, and its standard process doesn't reach a 90-day segment until after four weeks of solid open rates. BFCM is the definition of a volume spike, and Gmail warns against those without a sending history.

If your new domain won't be through Klaviyo's schedule before your BFCM sends, don't let the switch run into your biggest week. If you're replacing a domain, use "Move traffic with domain warming." If you can wait, switch after the holidays.

Either way, the advice I give before Black Friday still applies: set your offers as early as possible and build a full calendar that builds anticipation. A warmed domain with a weak plan still loses. My BFCM email strategy covers the plan.

What if my emails start going to spam during warming?

Stop widening. Klaviyo says to hold at your current segment when open rates drop below 20%, because that can mean your reputation is taking a hit. Then check the Spam and Bounce Rates graph in Klaviyo's trends report to find which campaign caused the spike.

Keep an eye on complaints. Gmail asks bulk senders to keep spam rates in Postmaster Tools below 0.10% and never reach 0.30%. Yahoo's limit is 0.3%.

If your emails are already landing in spam, work through why your Klaviyo emails are going to spam before you send anything bigger. And remove obviously bad profiles, but don't let list cleaning become the project. Capturing better profiles matters more.

FAQ

WRITTEN BY Jack White

Founder of Bardown Digital, a Chicago-based Klaviyo email and retention agency for Shopify brands. He's worked with brands doing $500K to $100M a year, with $100M+ in email-attributed revenue across them.

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