How Email List Cleaning Can Boost Open Rates, Reduce Spam Complaints & Save You Money
Keeping Your Email List Clean Just Got More Important
If you’re running email campaigns, you know that open rates, deliverability, and engagement matter. But here’s something many brands overlook—email list hygiene.
With Klaviyo raising its prices, every contact on your list needs to be worth keeping. A cluttered list filled with inactive subscribers, spam traps, and unengaged contacts isn’t just dragging down your metrics—it’s costing you money.
Let’s break down why email list cleaning is essential and how it can boost engagement, reduce spam complaints, and lower costs.
What Happens When You Don’t Clean Your Email List?
A bloated email list might look impressive, but if a large chunk of your subscribers aren’t opening, clicking, or engaging with your emails, it can hurt your email performance in ways you might not expect:
Lower Open & Click Rates – Sending to inactive subscribers skews your engagement metrics, making it harder to optimize campaigns.
Increased Spam Complaints – If people forget they subscribed or don’t find your emails relevant, they’ll mark them as spam.
Higher Bounce Rates – Old or invalid emails lead to more bounces, which damages your sender reputation.
Poor Deliverability – Email providers (Gmail, Yahoo, etc.) track your engagement. If your emails are consistently ignored, they’ll start landing in spam.
Unnecessary Costs – Email platforms like Klaviyo charge based on the number of subscribers. Keeping inactive contacts means paying for people who aren’t converting.
How to Clean Your Email List the Right Way
If you want higher open rates, better engagement, and lower costs, here’s what to do:
1. Identify & Remove Inactive Subscribers
If a subscriber hasn’t opened or clicked an email in 90+ days, they’re likely not interested anymore. Before removing them, send a re-engagement campaign to win them back. If they still don’t engage, it’s time to let them go.
2. Validate Email Addresses
Use an email verification tool (like ZeroBounce, NeverBounce, or Klaviyo’s built-in features) to remove fake, invalid, or mistyped emails that could be increasing your bounce rate.
3. Monitor Spam Complaints
If certain subscribers repeatedly mark your emails as spam, remove them immediately. Too many spam complaints can get your sender reputation flagged, affecting all future emails.
4. Segment Engaged vs. Unengaged Subscribers
Instead of sending every email to your entire list, create segments:
Highly engaged (opened/clicked in the last 30 days) – Send them frequent emails
Moderately engaged (last 60-90 days) – Reduce frequency or send targeted offers
Unengaged (90+ days inactive) – Send a re-engagement campaign, then remove if no response
5. Use Double Opt-In for New Subscribers
A double opt-in ensures only real, interested people join your list. This helps prevent fake emails, spam traps, and uninterested subscribers from bloating your list.
Why This Matters More Now Than Ever
With Klaviyo raising its prices, keeping a clean, high-quality list isn’t just about deliverability—it’s about saving money.
Every inactive subscriber you remove means:
Higher open rates
Better engagement
Lower spam complaints
Less money wasted on unresponsive contacts
The goal isn’t to have the biggest list—it’s to have the most engaged list.
Need Help Cleaning Up Your List?
At Milhook, we specialize in email and SMS marketing that actually drives revenue. Whether you need help optimizing your Klaviyo flows, improving deliverability, or setting up automated list cleaning, we’ve got you covered.
Let’s make sure your emails land in the inbox—and convert.
