You can craft the perfect subject line, write killer copy, and design a stunning email. But if it doesn’t land in your customer’s inbox, none of it matters.
Email deliverability is the silent driver of your success. It’s the difference between reaching your audience and vanishing into the spam folder. For eCommerce brands using Klaviyo in 2025, getting your deliverability right is essential, not optional.
Let’s explore exactly how to boost inbox placement by focusing on the key pillars: warming your sending behavior, setting up proper domain authentication, maintaining healthy IP practices, and using Klaviyo’s built-in tools to keep your sender reputation strong.
Why Email Deliverability Matters More Than Ever in 2025?
In a world where inboxes are crowded and email providers are stricter than ever, poor deliverability means lost revenue. When your emails land in spam or promotions tabs, fewer people open, click, or convert. That drives down your engagement rates and, in turn, damages your sender reputation, creating an even more vicious cycle.
Klaviyo provides tools to help, but you have to use them strategically. From day one, you should treat deliverability like a key performance metric, not an afterthought.
1. Set Up a Dedicated Sending Domain
If you’re still sending from a shared Klaviyo domain (like klaviyomail.com), you’re borrowing a reputation you can’t control. Switching to a dedicated sending domain gives you full ownership over how inbox providers view your messages.
This means setting up SPF, DKIM, and DMARC records for your domain and using a branded sender address. Klaviyo makes it easy to connect your domain and verify it, but it’s crucial to ensure DNS records are updated correctly.
A dedicated domain improves trust with inbox providers like Gmail and Outlook. Over time, they’ll learn to associate your domain with good sending behavior, increasing inbox placement rates.
2. Warm Up Your Sending Reputation Slowly
Whether you’re new to Klaviyo or just switched to a new domain, jumping in with a big send is a mistake. That’s a red flag for inbox providers.
Instead, gradually increase your sending volume over the first 2 to 3 weeks. Start with your most engaged subscribers, those who have opened or clicked on your content within the last 30 days. As your reputation builds, you can expand to include broader segments.
This “warming” period tells inbox providers, “I’m a good sender. People want my emails.” If you skip this step, your emails could get throttled, marked as spam, or blocked entirely.
3. Maintain a Clean List: Remove Unengaged Profiles
One of the fastest ways to damage deliverability is by emailing people who don’t open or click on your emails. High bounce rates, low engagement, and spam complaints all indicate to inbox providers that your content isn’t welcome.
Regularly clean your list by suppressing or removing unengaged contacts. In Klaviyo, use the segment builder to create dynamic lists like:
- Engaged in the last 30 days
- Opened at least 1 email in the last 5 campaigns
- Clicked in the last 60 days
Klaviyo also offers automated sunset flows, which gradually stop emailing subscribers who go cold. This protects your sender’s reputation while giving inactive users a final chance to re-engage.
4. Use Double Opt-In for Better Subscriber Quality
Quality beats quantity when it comes to email lists. Double opt-in ensures that subscribers genuinely want to hear from you and that their email address is accurate and valid. This reduces fake signups, typos, and spam traps, all of which hurt deliverability.
When someone signs up, they receive a confirmation email requesting verification. It may reduce list growth slightly, but the long-term benefits to deliverability are well worth it.
Klaviyo enables double opt-in with a simple toggle. For high-growth eCommerce stores, it’s a smart move, especially when scaling internationally.
5. Monitor Open and Click Rates and Adjust Frequency Accordingly
If your engagement rates dip, so does your deliverability. Keep a close eye on open rates, click-through rates, and unsubscribe metrics. These numbers indicate how inbox providers perceive your emails.
Klaviyo’s Campaign Performance Reports give you all the data you need. If you see open rates below 15% or spam complaints over 0.1%, that’s a warning sign.
You may need to send fewer emails to certain segments or test new subject lines to revive interest. Additionally, adjust your sending frequency according to how often users interact with your content. Sending daily emails to someone who hasn’t opened your last five messages is a recipe for disengagement.
6. Use Klaviyo’s Built-In Deliverability Tools
Klaviyo offers powerful tools to help you stay on top of deliverability:
- The segment builder allows you to create precise audiences, such as “Engaged in the last 30 days” or “Clicked a campaign but didn’t purchase.”
- Campaign Reports include deliverability insights, showing bounce rates, spam complaints, and engagement levels.
- Sunset Flows automatically phase out inactive subscribers without requiring any action on your part.
By using these tools regularly, you can make more informed decisions, send fewer low-performing emails, and maintain a strong deliverability rate.
Avoid Spam Triggers in Your Content
Even if your list and domain are solid, your content can still trigger filter flags. Avoid using all caps, excessive punctuation (like “BUY NOW!!!”), and too many salesy phrases in your subject lines.
Also, avoid attaching files, sending massive image-only emails, or stuffing your footer with a dozen links. Keep it clean, readable, and relevant. Ensure your unsubscribe link is easily accessible, and include a physical mailing address to remain compliant with CAN-SPAM laws.
Inbox Placement = Revenue Per Send
Improving deliverability isn’t just about avoiding spam folders; it’s about making every send count. If your emails consistently hit the inbox, your open rates go up, your click rates rise, and your revenue per email increases dramatically.
With Klaviyo, you have all the tools you need to manage deliverability like a pro. From warming up your domain to automating sunset flows, you can take full control of your sender reputation.
Treat your list with respect, send emails to engaged subscribers, and regularly monitor performance. Because in 2025, good email marketing isn’t just creative, it’s deliverable.
FAQs: Deliverability in Klaviyo
Should I use a dedicated sending domain in Klaviyo?
Yes. It builds trust with inbox providers and gives you more control over your reputation. Set up SPF, DKIM, and DMARC properly.
How long does it take to warm up a domain?
Generally, 2 to 3 weeks is the ideal timeframe. Start small with your most engaged users and gradually increase the volume.
What’s the best way to remove unengaged contacts in Klaviyo?
Use the segment builder to identify profiles that have not been active in 60–90 days. Pair that with automated sunset flows to manage it in the long term.
Is double opt-in necessary?
It’s not required, but strongly recommended. It improves list quality and reduces spam complaints and bounces.
What’s considered a good open rate in 2025?
Aim for at least 20%. Anything below 15% consistently means you need to clean your list or refine your targeting.
