- Products
- ResourceDEVELOPER
API
Clearout APIs are structured around REST and JSON
Webhooks
Capture real-time events in your application workflow
Form Guard
Real-time form validation to keep bad contacts out of your CRMKNOWLEDGE BASE
Getting started
Sending campaigns without bounces is made simple
FAQ
Easily find answers to services, security and common questionsUSE CASES
Lead Generation
Learn how professionals generate quality leadsGUIDESPricing
Transparent & flexible pricing to support pay-per-use or recurringEmail Verifier - Comparison AI-powered email verification with 99%+ accuracy, real-time validation, and transparent risk scoringEmail Finder - Comparison Pre-verified B2B email addresses with confidence scoring, find real person email, not role-based addressBLOGSEmail Verification ToolsHow To Build a Strong Sales Pipeline?View All Blogs - Pricing
- Integrations
- Enterprise
- Login
How to Get Rid of Invalid Subscribers in Kit (formerly ConvertKit)
Are your Kit (formerly ConvertKit) email campaigns struggling with sky-high bounce rates, low open rates, and disappointing engagement- even though you’ve already used the platform’s inbuilt cold subscriber filter?
You're not alone.
This is one of the most frustrating problems Kit users face- you follow best practices, remove inactive subscribers, yet your deliverability suffers.
Your emails land in spam. Your opens barely move. Your bounce rate creeps past 5%.
Why? Because Kit’s native filter only scratches the surface.
The real issue? Invisible email threats- invalid addresses, spam traps, and fake signups that never get flagged, but silently damage your sender reputation with every campaign you send.
If you're tired of watching your email performance tank despite doing everything ‘right’, it’s time to go beyond basic filters and finally clean your list properly.
You're not alone.
This is one of the most frustrating problems Kit users face- you follow best practices, remove inactive subscribers, yet your deliverability suffers.
Your emails land in spam. Your opens barely move. Your bounce rate creeps past 5%.
Why? Because Kit’s native filter only scratches the surface.
The real issue? Invisible email threats- invalid addresses, spam traps, and fake signups that never get flagged, but silently damage your sender reputation with every campaign you send.
If you're tired of watching your email performance tank despite doing everything ‘right’, it’s time to go beyond basic filters and finally clean your list properly.
What Is Kit (Formerly ConvertKit)?
Kit is a robust, intuitive email marketing platform designed keeping in mind online creators- bloggers, YouTubers, podcasters, and educators who want to grow their subscriber numbers and engage their audience without requiring complex tech setups.
The platform is known for bringing together two major factors- ease of use, and advanced automation features- making it especially popular among smaller teams and even those wanting to go solo.
The platform is known for bringing together two major factors- ease of use, and advanced automation features- making it especially popular among smaller teams and even those wanting to go solo.
These are the factors which make Kit stand out:
- Visual Automations: Build complex email funnels using a simple drag-and-drop interface
- Email Sequence Builder: Send drip campaigns with timed delivery and smart triggers
- Customisable Landing Pages and Forms: Capture leads without needing a separate tool or website
- Subscriber Tagging and Segmentation: Target subscribers based on behaviour, purchases, or interests
- Cold Subscriber Filter: Identify users who haven’t opened emails in the past 90 days
On one hand, Kit excels at content-focused email marketing, but its native list-cleaning features have their own share of limitations.
For people sending out high-volume campaigns or marketers managing third-party-acquired or old lists, bringing together Kit and an email verification tool like Clearout together becomes critical for maintaining a healthy list and upping your deliverability.
For people sending out high-volume campaigns or marketers managing third-party-acquired or old lists, bringing together Kit and an email verification tool like Clearout together becomes critical for maintaining a healthy list and upping your deliverability.
Clearout performs real-time checks to highlight all bad emails and even provides AI insights, Guaranteed Deliverables, Bounce detection and more ensuring campaigns are never a flop!
Kit is built with simplicity in mind. But when it comes to email list hygiene, Kit goes the best with Clearout, which provides an additional layer of email verification and data cleaning.
Kit is built with simplicity in mind. But when it comes to email list hygiene, Kit goes the best with Clearout, which provides an additional layer of email verification and data cleaning.
The Hidden Problem Behind Cold Subscribers
Kit’s cold subscriber filter identifies users who haven’t opened emails in the last 90 days. But this only shows one side of the story.
Not All Inactive Subscribers Are Bad Emails
It's a common misconception that inactivity automatically signals a bad or invalid email address. But in many cases, subscribers may appear inactive for reasons that have nothing to do with email validity.
Here’s why inactivity doesn’t always mean disengagement:
Here’s why inactivity doesn’t always mean disengagement:
- Secondary or Bulk Inbox Usage: Many subscribers subscribe mainly for newsletters or courses and may only check these messages occasionally.
- Seasonal or Sporadic Interest: Some users only engage during specific seasons, product launches, or promotions. Removing them could mean losing potential customers.
- Silent Fans: Some subscribers may not open or click emails but still consume content or follow you elsewhere (YouTube, social media, etc.).
Instead of blanket unsubscribing, consider re-engagement campaigns or segmented outreach before removal. Smart targeting can bring back valuable subscribers who aren’t truly lost. Some subscribers are still valid but simply haven’t interacted recently. They may be busy, use a secondary inbox, or have their activity hidden by privacy features like Apple Mail Privacy Protection.
You might be unsubscribing potential customers who could have been reactivated with the right messaging.
Not All Bad Emails Are Inactive
On the flip side, risky email accounts like disposable accounts, spam traps, or misspelled entries might appear active but are silently hurting your sender score.
These addresses can:
These addresses can:
- Cause hard bounces: When you send emails to invalid or non-existent addresses, email service providers (ESPs) mark your domain as unreliable, which leads to delivery issues.
- Get flagged by ESPs: ESPs monitor senders closely. A high volume of mail to fake or spam-trap addresses can result in your emails being flagged as spam or rejected outright.
- Harm your inbox placement: The more your emails get flagged or bounce, the more likely they are to end up in spam folders- even for your legitimate subscribers.
Inactivity ≠ Deliverability Risk
Here’s a breakdown of what Kit flags vs. what actually affects deliverability:
| Email Type | Kit Flags It? | Causes Deliverability Issues? |
|---|---|---|
| Misspelled/invalid | ❌ No | ✅ Yes |
| Disposable/temporary email | ❌ No | ✅ Yes |
| Role-based (info@...) | ❌ No | ✅ Yes |
| Spam traps | ❌ No | ✅ Yes |
| Inactive user | ✅ Yes | ✅ Maybe |
In short: Kit helps, but it's not enough.
You need a second line of defence..!
You need a second line of defence..!
Why You Need An Email Verification Layer
Relying solely on Kit’s cold subscriber filter is like locking your front door but leaving the windows open. It catches inactivity but misses the silent killers: spam traps, bots, disposable addresses, and typos. That’s where a dedicated email verification tool becomes indispensable.
The winning formula is-
Kit Cold Filter + Clearout Email Verification = Clean and High-Performing List
Email verification adds an extra layer of protection and performance that Kit alone can’t offer.
The winning formula is-
Kit Cold Filter + Clearout Email Verification = Clean and High-Performing List
Email verification adds an extra layer of protection and performance that Kit alone can’t offer.
Benefits of Adding Email Verification
- Reduce hard bounces below industry standards: Verified lists regularly keep bounce rates under 2%, which improves domain health and inbox delivery.
- Improve open and click-through rates: Once the invalids are gone, your metrics reflect only engaged, real subscribers.
- Protect your sender reputation: Avoiding spam traps and fake emails keeps your domain off blocklists.
- Lower campaign costs: Stop paying to send emails to addresses that don’t exist or never engage.
- Streamline segmentation: With clean data, you can target more effectively and personalise better.
Why Kit + Clearout is a Perfect Match
- Kit helps identify low-engagement users based on behavioral data.
- Clearout flags invalid, fake, and harmful addresses that behaviour data can't detect.
Whether you're nurturing leads, launching products, or running email-based courses, this two-layer system ensures your emails land where they should-in the inbox, not the spam folder.
The ideal approach combines Kit’s engagement filters with third-party email verification to fully protect your sender reputation.
The ideal approach combines Kit’s engagement filters with third-party email verification to fully protect your sender reputation.
Case Study- Rob Cairns
Rob, a digital marketer, had a 2,300-subscriber list that hadn’t been touched in years. His emails were bouncing at 3.3% to 5.4%.
After cleaning his list using a verification tool and updating his DNS records, he reduced his bounce rate to 0.25%.
Source: Weekend Growth - How I Reduced My Email Bounce Rate
These real-world results prove that email verification is not optional- it’s essential.
After cleaning his list using a verification tool and updating his DNS records, he reduced his bounce rate to 0.25%.
Source: Weekend Growth - How I Reduced My Email Bounce Rate
These real-world results prove that email verification is not optional- it’s essential.
How To Clean Your Kit List The Right Way
You can integrate Kit with Clearout for an additional security wall to ensure better deliverability and low bounce rates.
Step 1: Export Your Subscriber List
Go to Subscribers > All Subscribers > Export CSV
Step 2: Upload To Clearout For Verification
Use Clearout to scan for:
- Invalid emails
- Spam traps
- Role-based addresses
- Temporary/disposable emails
Step 3: Import the Clean List Back Into Kit
- Remove or tag bad contacts
- Re-import verified subscribers
Step 4: Use Kit’s Cold Subscriber Filter Regularly
- Segment subscribers who haven’t opened emails in 90+ days
- Unsubscribe or retarget with a re-engagement campaign
Pro Tips To Maintain A Healthy List
- Automate list cleaning by using Zapier to sync Kit with Clearout
- Tag risky contacts instead of deleting immediately
- Re-engage cold leads with personalised offers or surveys
- Clean your list quarterly, especially before product launches or seasonal promos
Final Thoughts
Kit (formerly ConvertKit) is a fantastic tool for creators, but if you're serious about results, email list hygiene needs to be your priority. It's cold subscriber filter is helpful, but far from bulletproof.
By combining Kit’s built-in features with a robust email verification tool like Clearout, you’ll:
By combining Kit’s built-in features with a robust email verification tool like Clearout, you’ll:
- Deliver more emails to inboxes
- Protect your sender reputation
- Boost your engagement
- Reduce costs
Start cleaning your Kit list today and experience the results for yourself.
FAQs
How do I find cold subscribers in Kit?
To find cold subscribers in Kit, you can use Kit’s filter to segment anyone who hasn’t opened emails in the last 90 days.
You can then tag, unsubscribe, or export the contact.
You can then tag, unsubscribe, or export the contact.
Why are my Kit emails bouncing?
Common reasons for your kit email bounce back include fake or mistyped emails, expired domains, and spam traps.
Kit doesn’t automatically catch all of these, you need to rely on a strong email verifier to mark and get rid of all bad emails that damage campaign deliverability.
Kit doesn’t automatically catch all of these, you need to rely on a strong email verifier to mark and get rid of all bad emails that damage campaign deliverability.
What’s a good bounce rate for email marketing?
Anything below 3-4% is considered a healthy bounce rate for email marketing.
Higher bounce rates can damage your sender reputation. With tools like Clearout you can easily maintain an email list that has less than 3% bounce rate.
Higher bounce rates can damage your sender reputation. With tools like Clearout you can easily maintain an email list that has less than 3% bounce rate.
Should I delete or unsubscribe cold subscribers?
Start by unsubscribing. Deleting removes data permanently; unsubscribing lets you retarget later if needed for re-engaging.
How often should I clean my email list?
You should clean your email list every 2-3 months or before launching a new campaign.