What are the best alternative deliverability tools to Kickbox after its shutdown?
Michael Ko
Co-founder & CEO, Suped
Published 26 Jul 2025
Updated 17 Aug 2025
7 min read
The news of Kickbox's deliverability tools shutting down on January 15, 2024, came as a significant blow to many in the email marketing and deliverability community. Kickbox provided valuable services for email verification and testing, and its absence leaves a gap that many are now scrambling to fill. Finding a robust alternative is critical to maintaining high inbox placement rates and protecting sender reputation.
For businesses relying on proactive monitoring and hygiene, this shutdown necessitates a quick transition to new platforms. The goal is to identify tools that not only replicate Kickbox's core functionalities but also offer enhanced features and comprehensive support. This article explores the best alternative deliverability tools available to ensure your email program remains effective and compliant.
Understanding the impact of Kickbox’s shutdown
The sudden departure of a widely used tool like Kickbox means that many email senders and deliverability professionals are now seeking comprehensive solutions to manage their email programs. Kickbox was known for its email verification service, which helped users clean their lists, reduce bounce rates, and avoid spam traps. While verification is a crucial aspect, Kickbox also offered deliverability testing to predict inbox placement.
The challenge now is to find a platform that offers both reliable email deliverability monitoring outside an ESP and robust email verification, without compromising on data accuracy or regional coverage, especially for European ISPs. Without continuous monitoring, you risk falling victim to blocklists (or blacklists) and experiencing significant drops in inbox placement, impacting your marketing efforts and transactional communications.
The impact on deliverability
The void left by Kickbox highlights the critical need for constant vigilance in email deliverability. A lapse in monitoring can quickly lead to degraded sender reputation, increased bounce rates, and emails landing in the spam folder. This directly impacts revenue, engagement, and overall communication effectiveness. Proactive testing and list hygiene are non-negotiable for success.
Why robust alternatives are essential
The market offers several alternatives, but choosing the right one requires careful evaluation. You need a solution that provides accurate insights into inbox placement, identifies potential issues like spam traps or blocklistings, and supports compliance with sender requirements from major mailbox providers. The right tool can help navigate the complex landscape of email delivery.
Essential features for a new deliverability partner
When evaluating new deliverability tools, it is essential to look beyond basic email verification. A comprehensive solution should offer a suite of features that address various aspects of email deliverability issues. This includes everything from initial email list health to ongoing performance monitoring. Think about what your team needs to effectively troubleshoot and optimize email campaigns.
Key features to prioritize include robust inbox placement testing across a diverse range of ISPs globally and regionally. This is particularly important for those who rely on extensive European ISP coverage. Furthermore, active blacklist monitoring and spam trap detection capabilities are vital to prevent reputation damage. Consider how well a tool integrates into your existing workflow and if it provides actionable insights, not just raw data.
Another crucial aspect is comprehensive support for email authentication protocols like SPF, DKIM, and DMARC. Ensuring these are correctly configured is foundational to deliverability. Many tools offer insights into DMARC reports, helping you identify authentication failures and unauthorized sending. Look for tools that provide clear diagnostics and guidance for improving your email program’s health.
Feature
Description
Importance
Inbox placement testing
Measures where emails land, including inbox, spam, or missing, across various ISPs.
Crucial for understanding campaign effectiveness and identifying filtering issues.
Blacklist monitoring
Alerts if your sending IP or domain is listed on major blocklists.
Essential for preventing email blocking and maintaining sender reputation.
Email authentication analysis
Validates SPF, DKIM, and DMARC configurations and compliance.
Foundational for establishing trust with mailbox providers and preventing spoofing.
Spam trap detection
Identifies email addresses that are actually spam traps on your list.
Helps protect sender reputation by removing harmful addresses from your lists.
Leading alternatives for robust deliverability monitoring
Several platforms have emerged as strong contenders to replace Kickbox, each with its unique strengths. Many of these tools excel in either email verification or deliverability monitoring, or sometimes both. For comprehensive all-round deliverability tracking, a combination of tools or a single robust platform might be necessary. It’s vital to assess your specific needs before committing.
Some top alternatives for email verification include ZeroBounce and Bouncer. Both offer robust email validation services, helping to reduce hard bounces and improve list quality. For Bouncer's Deliverability Kit, it is designed to be a user-friendly and robust option. Email Industries also provides a comparative view of several deliverability vendors, which can be a helpful starting point for your research. These platforms focus on ensuring your emails reach valid inboxes, preventing hits to your sender reputation from invalid addresses.
For deliverability testing and monitoring, options like GlockApps and Everest (by Validity) are widely recognized. These tools provide insights into inbox placement rates across various mailbox providers, offer email blacklist checks, and help diagnose sending issues. While Everest is a comprehensive, enterprise-level solution, other tools might be more suitable for smaller teams or specific audit needs, as its pricing can be substantial.
Other notable mentions include Inbox Monsters, InboxReady, and eDataSource by MessageBird, which also provide robust deliverability monitoring capabilities. When comparing these, consider the depth of their analytics, the diversity of their seed lists (especially for international coverage), and how frequently their data is updated. Some platforms might offer free tiers or trials, which can be useful for testing before committing.
Everest: A comprehensive suite from Validity for inbox placement, reputation, and authentication.
Cons
Pricing: Some comprehensive tools can be costly, especially for smaller businesses.
Complexity: Some platforms might have a steeper learning curve for new users.
Beyond tools: Strengthening your deliverability foundation
While specialized tools are invaluable, achieving top-tier email deliverability extends beyond using a single platform. A holistic approach involves consistent adherence to email deliverability best practices, focusing on aspects that directly influence how mailbox providers view your sending reputation. This includes maintaining a clean email list, engaging content, and proper email authentication.
Always prioritize permission-based email marketing to ensure recipients genuinely want your emails. Implement a clear and easy unsubscribe process. Regularly clean your lists to remove inactive subscribers, hard bounces, and any identified spam traps. A clean list translates to better engagement metrics and a stronger sender reputation.
Technical configurations are equally vital. Ensure your SPF, DKIM, and DMARC records are correctly set up and aligned. Microsoft and Google's recent requirements emphasize the importance of these authentication protocols, especially for bulk senders. A strong authentication setup reduces the likelihood of your emails being flagged as spam or rejected outright.
Remember, email deliverability is an ongoing process, not a one-time fix. Regularly monitor your sender reputation, analyze your campaign performance, and adapt your strategies based on feedback from mailbox providers and your chosen deliverability tools. Proactive management and adherence to best practices will serve you well in navigating the complexities of email delivery.
Views from the trenches
Best practices
Always maintain a clean email list by regularly removing inactive or invalid addresses, reducing bounces and spam trap hits.
Implement DMARC with a monitoring policy to gain visibility into your email authentication status and identify potential spoofing.
Ensure strong consent practices, only sending to recipients who have explicitly opted in to receive your emails.
Segment your audience and personalize content to improve engagement metrics, which positively influences deliverability.
Monitor your sender reputation continuously using tools and postmaster insights to quickly address any issues.
Common pitfalls
Neglecting email list hygiene, leading to high bounce rates and potential blocklistings.
Ignoring DMARC reports, missing critical insights into authentication failures and unauthorized sending.
Sending emails to purchased or old lists, increasing the risk of hitting spam traps and complaints.
Failing to implement proper SPF and DKIM records, which can cause emails to fail authentication checks.
Over-sending to unengaged subscribers, negatively impacting your sender reputation over time.
Expert tips
Diversify your seed list with a wide range of global and regional ISPs, especially European ones, for comprehensive testing.
Look for deliverability tools that provide actionable advice, not just data, to help you resolve issues efficiently.
Consider a phased approach when migrating to a new tool, running parallel tests to compare performance.
Engage with the email community; forums and Slack channels can offer quick insights and shared experiences.
Focus on content relevance and email design to boost engagement, which is a strong signal to mailbox providers.
Marketer view
Marketer from Email Geeks says they were disappointed by Kickbox's shutdown, expressing frustration over the loss of its deliverability tools.
2023-10-19 - Email Geeks
Marketer view
Marketer from Email Geeks says they need alternatives with an extensive list of European ISPs, noting they can provide access to French mailboxes for testing.
2023-10-19 - Email Geeks
Moving forward with confidence
The shutdown of Kickbox's deliverability tools marks a significant shift in the email deliverability landscape. While it presents a challenge, it also offers an opportunity to re-evaluate and enhance your email strategy with more robust and comprehensive solutions. The key is to select tools that not only meet your immediate needs for verification and monitoring but also align with your long-term deliverability goals.
By focusing on essential features like accurate inbox placement testing, reliable blocklist (or blacklist) monitoring, and robust email authentication, you can ensure your email program remains healthy and effective. Remember to pair your chosen tools with foundational email marketing best practices, such as list hygiene and proper consent, for optimal results.
Kickbox's deliverability tools shutting down on January 15, 2024, came as a significant blow to many in the email marketing and deliverability community. Kickbox provided valuable services for email verification and testing, and its absence leaves a gap that many are now scrambling to fill. Finding a robust alternative is critical to maintaining high inbox placement rates and protecting sender reputation.
ZeroBounce and 
Bouncer. Both offer robust email validation services, helping to reduce hard bounces and improve list quality. For Bouncer's Deliverability Kit, it is designed to be a user-friendly and robust option. Email Industries also provides a comparative view of several deliverability vendors, which can be a helpful starting point for your research. These platforms focus on ensuring your emails reach valid inboxes, preventing hits to your sender reputation from invalid addresses.
GlockApps and Everest (by 
Validity) are widely recognized. These tools provide insights into inbox placement rates across various mailbox providers, offer email blacklist checks, and help diagnose sending issues. While Everest is a comprehensive, enterprise-level solution, other tools might be more suitable for smaller teams or specific audit needs, as its pricing can be substantial.
