What are the best alternative tools to GlockApps for inbox testing due to false positives and pricing issues?
Matthew Whittaker
Co-founder & CTO, Suped
Published 13 May 2025
Updated 19 Aug 2025
7 min read
Achieving high email deliverability is a constant challenge for marketers and businesses. Knowing whether your emails are reaching the inbox or landing in spam folders is crucial, and that's where inbox testing tools come in. For years, tools like GlockApps have been a go-to for many, providing insights into email placement across various internet service providers (ISPs).
However, recent updates to some popular platforms have introduced concerns regarding false positives and changes to pricing structures, prompting many to seek reliable alternatives. I've seen a growing number of conversations among email professionals expressing frustration with these issues, particularly with how new seed lists are performing and the impact on overall testing accuracy. This shift makes it important to explore other options that offer consistent and dependable results, especially for senders managing both dedicated IPs and various Email Service Providers (ESPs).
The challenges with current inbox testing tools
The core issue with some of these updates appears to stem from the introduction of new seed lists that can generate misleading inbox placement results. It's incredibly frustrating when tests indicate a spam placement, but further investigation reveals that emails are indeed landing in the inbox. This discrepancy wastes valuable time and resources, as teams then chase phantom problems. The feeling of not being able to fully trust your primary inbox testing tool can undermine your entire deliverability strategy.
Beyond accuracy, pricing structure changes have also caused significant friction for users. Increased costs, particularly for a limited number of credits, make it difficult for businesses to conduct the frequent, in-depth testing required for optimal performance. When the cost-benefit analysis no longer adds up, it's a clear signal to explore other vendors that offer more transparent and affordable models without compromising on quality or functionality.
Many users have reported issues with secure connections like TLS and SSL after recent updates, particularly with the removal of port 25 support. While the intent might be to enhance security, these changes have inadvertently created compatibility problems for properly configured sending accounts. This can lead to a significant number of failed tests and an inability to get an accurate read on email deliverability, pushing users to find platforms with more robust and adaptable technical infrastructures.
Furthermore, the lack of responsive support exacerbates these challenges. When facing critical deliverability issues, timely assistance is paramount. Delays in troubleshooting due to time zone differences or limited support channels can mean lost revenue and damaged sender reputation. A reliable alternative should offer not only accurate testing but also accessible and efficient customer support to resolve issues promptly.
Key features for effective deliverability testing
When evaluating alternatives, the primary concern is accuracy. The tool must provide reliable insights into where your emails are landing, distinguishing between the inbox, spam folder, or specific tabs like Gmail's Promotions tab. An ideal inbox placement tool should minimize false positives and offer a clear, actionable breakdown of results that truly reflects deliverability.
Another crucial feature is comprehensive reporting. This includes not just placement rates but also insights into authentication statuses (SPF, DKIM, DMARC), content analysis, and blocklist (or blacklist) checks. Detailed reports help pinpoint specific issues, whether it's a misconfigured DMARC record or a triggered spam filter. The ability to integrate with different sending infrastructures, including dedicated IPs and various ESPs, is also vital for flexibility.
Consideration should also be given to the user interface and support. An intuitive interface makes it easy to set up tests, interpret results, and track trends over time. Responsive and knowledgeable customer support can be the difference between quickly resolving a critical deliverability issue and prolonged inbox placement problems.
Top alternatives for comprehensive inbox placement
Several tools have emerged as strong contenders for those seeking alternatives to GlockApps. Each offers unique strengths, catering to different needs and budgets. ZeroBounce, for instance, has been highlighted for its recent improvements in inbox placement testing. It is recognized for its accuracy and comprehensive suite of email verification services, although it may not distinguish between Gmail's primary and promotions tabs.
Another notable alternative is Inbox Monster. While it might be on the pricier side, it offers advanced capabilities, including the ability to distinguish between different Gmail tabs, which is a significant advantage for marketers. Its detailed reporting can provide deeper insights into how your campaigns perform across various inbox environments.
Additionally, tools like MailerCheck and InboxAlly are gaining traction. InboxAlly is lauded as a powerful monitoring platform that often outperforms competitors, offering comprehensive insights. These platforms aim to provide robust testing environments that accurately reflect real-world deliverability, crucial for optimizing email campaigns.
Accuracy and reporting
Seed lists: Ensure the service uses a diverse and regularly updated seed list to provide accurate reflections of inbox placement, including distinctions for promotional tabs.
Diagnostic detail: Look for detailed reports that explain why an email landed in spam or a specific tab, often including blocklist checks and content analysis.
Cost-effectiveness
Pricing model: Compare credit-based systems vs. subscription models. Choose what aligns best with your sending volume and testing frequency.
Value for money: Evaluate the features offered against the price point. A higher price might be justified for comprehensive features like advanced reporting.
Beyond basic testing: A holistic deliverability strategy
While inbox testing tools are essential, they are just one component of a robust email deliverability strategy. To ensure your emails consistently reach the inbox, you need a holistic approach that covers various technical and content aspects. This includes ensuring your email authentication records like SPF, DKIM, and DMARC are correctly configured and aligned.
Monitoring your sender reputation through tools like Google Postmaster Tools, alongside regular blocklist monitoring, is also vital. A clean sending reputation directly impacts inbox placement. Issues such as high bounce rates or spam complaints can quickly lead to your emails being directed to the spam folder, or even blocked entirely.
Finally, regular auditing of your email content for spammy keywords, broken links, or poor formatting can significantly improve deliverability. Maintaining a healthy mailing list by regularly cleaning unengaged subscribers and removing invalid addresses also prevents damage to your sender reputation and helps to avoid emails going to spam.
Views from the trenches
Best practices
Use diversified seed lists across multiple testing tools to get a more comprehensive and accurate view of inbox placement.
Regularly monitor your email authentication records, including SPF, DKIM, and DMARC, for proper configuration.
Segment your audience and tailor content to improve engagement, which positively impacts deliverability.
Common pitfalls
Over-reliance on a single inbox testing tool's data, especially if it shows a history of false positives.
Ignoring the impact of poor list hygiene and unengaged subscribers on your sender reputation.
Neglecting to monitor your IP and domain reputation for any blacklisting or blocklisting events.
Expert tips
Invest in tools that provide detailed diagnostic reports beyond simple inbox placement, such as content analysis.
Prioritize tools with responsive and knowledgeable customer support, as timely assistance is crucial for deliverability issues.
Consider the overall cost-effectiveness, looking beyond just per-test pricing to long-term value and features.
Marketer view
Marketer from Email Geeks says they recently introduced a new inbox placement testing section which they like a lot and are thinking of switching to it.
2024-01-04 - Email Geeks
Marketer view
Marketer from Email Geeks says they feel the UI of some testing tools was made by someone who never used the tool, finding it not intuitive at all.
2024-01-04 - Email Geeks
Finding the right fit for your deliverability needs
Navigating the complexities of email deliverability requires robust tools that provide accurate and actionable insights. While some existing platforms may present challenges with false positives, usability, or pricing, a range of alternative solutions are available. Exploring these options can help you find a tool that aligns better with your specific needs, whether you're managing dedicated IPs or leveraging multiple ESPs. Remember, the goal is to consistently land your emails in the inbox, and the right tools are key to achieving that objective.
Beyond just choosing a new inbox testing tool, adopting a comprehensive deliverability strategy is paramount. Regular testing, coupled with strong authentication, reputation management, and content optimization, will significantly improve your chances of successful email delivery. By focusing on these core pillars, you can overcome common hurdles and ensure your messages reach their intended audience.
