When Was the Last Time You Cleaned Your Mailing List?

When Was the Last Time You Cleaned Your Mailing List?

Most people think a bigger list is always better. It’s not.

Gmail and Yahoo are watching your spam complaint rate – it needs to stay under 0.3%, and ideally under 0.1%. Low engagement is actually a bigger red flag to their filters than list size. A smaller list that opens your emails will consistently outperform a huge list that ignores them, because inbox providers reward the senders their users actually want to hear from – and quietly bury the ones they don’t.

If you’ve never gone in and removed the people who never open your emails, this is your sign.

Why a Smaller, Engaged List Beats a Bigger One

Every email you send to someone who never opens it is a small signal to Gmail and Yahoo that your emails might not be wanted. Enough of those signals, and their filters start routing all of your emails to spam or junk — including the ones to people who genuinely want to hear from you. Removing your least-engaged subscribers isn’t shrinking your business. It’s protecting the inbox placement of everyone who’s actually paying attention.

How to Find Your Inactive Subscribers

Here’s exactly where to look, platform by platform, to build a list of subscribers who haven’t opened anything from you in the last 90 days.

Mailchimp

1. Go to Audience, then Segments.
2. Click Create Segment.
3. Under your first filter, choose Email subscription status → is one of → Subscribed.
4. Click + Add filter for a second condition.
5. Choose an email engagement filter and set it to subscribers who didn’t open or click any campaign in the last 90 days.
6. Save the segment — this is your inactive list.

Klaviyo

1. Go to Lists & Segments, then create a new segment.
2. Set the definition to: Can receive email marketing AND Received Email is at least 5 over all time AND Opened Email 0 times in the last 90 days AND Clicked Email 0 times in the last 90 days.
3. Save the segment. (The “received at least 5” condition matters — it filters out brand-new subscribers who simply haven’t had a chance to open anything yet.)

Omnisend

1. Go to Audience → Segments → Create segment.
2. Choose Pre-built segment → Disengaged contacts → Inactive contacts (or build it manually: have not opened a message at least once in the last 90 days, connected with AND to have not clicked a message in the last 90 days).
3. Save the segment.

What to Do With That List

Once you have it, you’ve got two honest options:

1. Send one re-engagement email. Ask them directly if they still want to hear from you — something as simple as “Still want these emails?” with a clear yes/no. Anyone who doesn’t respond or click after that gets removed.
2. Remove them outright. If you already know this group is dead weight — old customers, people who signed up years ago for a giveaway, generic curiosity clicks — skip the re-engagement step and clean the list straight away.

Either way, do it before your next big send, not after. A clean list is one of the simplest, fastest things you can do to protect how many people actually see your emails going forward.