Top 5 AI Tools For Spam Filtering 2025

Email spam is evolving faster than ever, with 51% of spam now AI-generated and phishing campaigns incorporating AI in 82.6% of cases. Traditional methods struggle to keep up, misclassifying 73.7% of AI-modified spam as legitimate. To combat this, AI-powered spam filtering tools have become essential for businesses, offering advanced detection capabilities, integration with popular platforms, and scalability to handle growing email volumes.

Here are the top 5 AI spam filtering tools of 2025:

• Inbox Agents: Focuses on high detection accuracy using LLMs, real-time sender analysis, and seamless integration with platforms like Microsoft 365 and Google Workspace.
• Abnormal AI: Uses behavioral profiling to detect anomalies in communication patterns and employs autonomous AI agents for real-time threat neutralization.
• Avanan: Scans emails post-delivery to catch threats missed by standard filters, offering explainable AI insights and integration with collaboration tools.
• GlockApps: Specializes in pre-send testing to improve email deliverability across major providers like Gmail and Outlook.
• Proofpoint Essentials: Tailored for SMBs, it blocks 99.99% of threats and integrates easily with Microsoft 365 and Google Workspace.

Quick Comparison

Tool	Detection Accuracy	Key Features	Integration	Best For
Inbox Agents	High	LLM detection, sender graph analysis	Microsoft 365, Google Workspace	Individuals, small teams
Abnormal AI	High	Behavioral profiling, autonomous agents	Microsoft 365, Slack, Zoom	Large enterprises
Avanan	Very High	Explainable AI, post-delivery scanning	Microsoft 365, collaboration tools	Enterprise-level protection
GlockApps	Moderate	Pre-send testing, deliverability insights	Email services, Google Postmaster	High-volume senders
Proofpoint	Very High	Threat graphing, real-time protection	Microsoft 365, Google Workspace	SMBs

AI spam filters are critical for reducing risks and ensuring email security in 2025. Whether you're a small business or a large enterprise, choosing the right tool depends on your email volume, security needs, and budget.

Can AI Block Spam?

1. Inbox Agents

Inbox Agents combines advanced messaging tools with AI-driven spam filtering to provide robust email protection for high-volume users.

Spam Detection Accuracy

The platform leverages cutting-edge multi-modal LLM detection to identify even the most advanced threats, such as image-based phishing attempts and scams generated by AI. By using natural language processing (NLP) for intent classification and real-time sender graph analysis powered by adaptive machine learning ensembles, Inbox Agents can detect subtle signs of phishing and credential theft . These insights feed directly into its AI system, which continuously refines its filtering strategies.

AI and Machine Learning Capabilities

Inbox Agents employs an AI system that learns from previous interactions to fine-tune its filtering process. This ensures genuine emails are delivered while adapting to block emerging spam threats. This dynamic learning capability forms the backbone of its ability to integrate with various platforms and scale efficiently.

Integration with Other Platforms

The platform integrates effortlessly with major cloud email services like Microsoft 365, Google Workspace, Zoho Mail, Rackspace, and FastMail. Setup is straightforward - just update your MX records, and you're ready to go in under five minutes. This seamless process ensures consistent email protection across all channels.

Scalability for Different Organization Sizes

Built on a cloud-based architecture, Inbox Agents scales smoothly with your organization's growth. It offers tiered pricing plans: Basic for individual users, Professional for those with advanced needs, and Enterprise for larger teams. The AI system continues to evolve, learning from new spam tactics and automatically adapting to growing email volumes - eliminating the need for manual updates.

2. Abnormal AI

Abnormal AI takes a behavioral approach to spam filtering by creating dynamic profiles that reflect how your organization communicates. Instead of sticking to static rules, it examines sender-recipient relationships, typical email send times, and subject line trends to define what "normal" communication looks like for each user. If an email strays from these established norms, the system flags it for further review.

Spam Detection Accuracy

The platform uses a dual-layer machine learning system - combining supervised learning for known attack patterns with unsupervised learning to identify new threats. By applying natural language processing (NLP) to assess tone, urgency, and intent, it has achieved a 90% reduction in phishing attacks. This context-aware model also significantly reduces false positives compared to traditional rule-based systems.

"Within four days of implementation, Abnormal identified a Business Email Compromise (BEC) email that had successfully bypassed Microsoft 365's native filters."
– Blaine Carter, Global CIO, FranklinCovey

AI and Machine Learning Capabilities

Beyond detection, the platform leverages AI automation to enhance security further. Abnormal deploys autonomous AI agents that can neutralize threats in milliseconds while continuously learning from evolving attack methods. For example, the "Quarantine Release" agent quickly isolates suspicious emails, and "URL Rewriting" examines links in real time before users can interact with them. Additionally, its specialized knowledge bases - PeopleBase, VendorBase, and ThreatBase - aggregate behavioral insights across platforms, adapting to new threats without requiring manual updates.

Integration with Other Platforms

Abnormal integrates seamlessly through native API connections with Microsoft 365, Google Workspace, Slack, and Zoom. According to Noah Davis, CISO of Ingersoll Rand, the platform protected all company accounts in under 15 minutes using its one-click setup. This effortless integration complements its advanced detection capabilities, making it a valuable tool for organizations of any size.

Scalability for Different Organization Sizes

The platform’s design ensures it scales effortlessly to meet the needs of organizations big and small. Abnormal currently supports over 3,000 customers, including 25% of the Fortune 500. Its autonomous features reduce manual SOC workloads by 95%, making it equally effective for smaller security teams and large enterprises. For instance, Avery Dennison’s security team reclaimed 40 hours per week after implementing the system, enabling them to focus on more strategic initiatives. Thanks to its API-based architecture, the platform scales instantly without requiring infrastructure changes.

3. Avanan

Avanan, now part of Check Point Harmony, uses an API-based inline deployment to scan emails after they pass through standard security filters. This approach targets attacks that manage to bypass tools like Microsoft EOP. By processing over 360 million emails, Avanan fine-tunes its detection algorithms, achieving an impressive 99.2% reduction in phishing attacks. This extensive database forms the backbone of its highly accurate detection capabilities.

Spam Detection Accuracy

Avanan's AI-driven technology taps into data from more than 23,000 customers to identify elusive spam patterns. According to Check Point's analysis, Avanan's solution is 15 times more effective than traditional gateways and 18 times better than Microsoft ATP at catching sophisticated threats. Its anomaly engine works by creating behavioral profiles based on factors like login locations, data transfer habits, and frequent email contacts, enabling it to identify compromised accounts. Organizations using Avanan have seen a 71% drop in end-user alerts sent to their Security Operations Center.

AI and Machine Learning Capabilities

What sets Avanan apart is its explainable AI, which allows administrators to understand exactly why an email was flagged. The system analyzes elements like text sentiment, sender reputation, brand usage, and attachment properties. Its AI models evolve continuously, learning from new data and user feedback to reduce false positives and adapt to new threats. Bijender Mishra, Chief Information Security Officer at Alkem Laboratories, shared his confidence in the platform:

Check Point gives me peace of mind, knowing that we have the best security solution to protect Alkem.

Avanan's capabilities extend beyond email, applying its AI-driven filtering to collaboration tools like Microsoft Teams, Slack, Dropbox, and Box. These explainable insights make Avanan a proactive solution in the fight against modern spam and phishing threats.

Integration with Other Platforms

Avanan's advanced detection capabilities integrate seamlessly via API with Microsoft 365, Google Workspace, and other major collaboration platforms - all without requiring changes to MX records. Robert Melendez, Vice President of Information Technology at Makeready, praised the integration:

The product integrates wonderfully with Microsoft 365. It's built right on a cloud platform and works almost natively.

The platform ensures email security in all directions - internal, external, and outgoing - while remaining invisible to hackers. Its "Search and Destroy" feature allows administrators to remove phishing emails from all user inboxes with just one click once a threat is identified.

Scalability for Different Organization Sizes

Avanan is designed to accommodate organizations of all sizes. With more than 5,000 customers and a 9.2/10 rating on PeerSpot, its flexible user-based pricing model adapts to the needs of any business . Notably, 60% of its users are large enterprises. The platform's effectiveness has earned it recognition as a Leader in the 2025 Gartner Magic Quadrant for Email Security .

sbb-itb-fd3217b

4. GlockApps

GlockApps stands out on our list of top AI tools for spam filtering by taking a different approach. Instead of focusing on real-time blocking, it specializes in testing how emails perform across major providers like Gmail, Yahoo, and Outlook. Using seed lists of real professional and personal accounts, GlockApps simulates actual delivery conditions to provide insights into email deliverability.

Spam Detection Accuracy

GlockApps evaluates emails through third-party filters and offers practical steps to address issues that might trigger spam filters. Beyond analyzing content, it also tracks technical factors like SPF, DKIM, and DMARC authentication, as well as over 50 IP and ESP blacklists. According to GlockApps' Q1 2025 data, inbox placement rates for high-volume senders (those sending over 1 million emails monthly) dropped by 22.35% compared to the previous year. Gmail led the pack with the highest inbox placement rate among major ISPs, reaching 70.7% in recent benchmarks. These insights highlight the importance of pre-send testing, which GlockApps uses AI to refine.

AI and Machine Learning Capabilities

GlockApps leverages AI to analyze email content, subject lines, and sender addresses, identifying potential spam triggers before emails are sent. Its machine learning algorithms mimic how major ISP spam filters evaluate messages, offering actionable recommendations to improve deliverability. The tool also flags high-risk elements like sales-heavy language, suspicious links, and poor text-to-image ratios, which are common triggers for modern spam filters. In Q2 2025, Outlook had the highest spam rate among major providers, hitting 47.31%.

Integration with Other Platforms

GlockApps enhances its spam detection with seamless integration into key email services. It connects with tools like DMARC Analyzer, SPF/DKIM checkers, and an uptime monitor for technical testing. For advanced users, the Bundle plans include integration with Google Postmaster Tools, providing direct reputation data from Google. Additionally, the platform features "Gappie", a monitoring tool that sends alerts about deliverability issues.

Scalability for Different Organization Sizes

Designed for enterprise teams and high-volume senders, GlockApps delivers tailored insights into how different providers filter emails. Pricing starts at $59 per month for the Essentials Bundle and goes up to $129 per month for the Enterprise Bundle, with test packs available from $16.99. The platform maintains a 4.6/5 user rating and a 4.8/5 rating on Capterra, though some users have mentioned concerns about its complex pricing structure and monthly credit expirations. For those needing additional support, GlockApps offers deliverability consulting services at $300 per hour through its partnership with MailSoar.

5. Proofpoint Essentials

Proofpoint Essentials provides robust email protection tailored for small and medium-sized businesses (SMBs). It blocks 99.99% of threats and processes over 3.4 trillion emails annually, offering enterprise-level security to organizations with limited resources. Here's a closer look at its standout features, from spam detection to seamless integration and scalability.

Spam Detection Accuracy

Proofpoint Essentials excels in spam detection, achieving a 98% accuracy rating from SE Labs and blocking over 99% of spam emails. Its advanced Proofpoint Nexus Platform combines multiple AI technologies for comprehensive protection. It uses language models to identify transactional cues linked to business email compromise (BEC), maps typical communication patterns with its Nexus Relationship Graph to detect impersonation attempts, and employs Computer Vision to spot malicious QR codes and brand spoofing.

AI and Machine Learning Capabilities

This platform leverages automation to classify, prioritize, and remove harmful messages across the globe. With TensorFlow integration, it blocks an additional 100 million spam emails daily, adapting continuously to new threats like TOAD (telephone-oriented attack delivery). Gartner has recognized Proofpoint as a Leader in the 2025 Magic Quadrant for Email Security, underscoring its advanced capabilities.

"Proofpoint is the only vendor that delivers on all five areas for email security as an integrated platform".

Integration with Other Platforms

Proofpoint Essentials integrates seamlessly with Microsoft 365 and Google Workspace. Its API-based deployment allows for quick setup - often within minutes - without requiring changes to MX records. For those using Secure Email Gateways (SEG), it provides pre-delivery and click-time protection. Real-time warning banners further enhance user awareness by flagging potentially suspicious emails.

Scalability for Different Organization Sizes

Though it serves 85 Fortune 100 companies, Proofpoint Essentials is designed with SMBs in mind, offering pricing as low as $3 per user per month. Its cloud-based architecture ensures rapid scalability, making it a flexible choice for growing businesses. The platform has garnered strong user reviews, including a 4.6 rating on G2, 5 on Capterra, and 4.7 on Trustpilot. While users praise its accuracy and reliability, some have noted occasional email delays and a lack of advanced features in its basic plans.

Feature Comparison

Choosing the right spam filtering tool depends on your organization's size, budget, and security needs. Each tool uses AI in its own way, offering distinct features and pricing options. Here's a breakdown of what makes each stand out, based on their individual reviews.

Inbox Agents is tailored for individuals and small teams. Its AI adapts to user behavior, making it a budget-friendly choice at just $5 per month.

Abnormal AI takes a different approach, using behavioral AI to spot irregularities in communication patterns. Andy Albrecht, CISO at Domino's, highlights its unique strength:

Abnormal's differentiator is its behavioral AI. Abnormal knows the company's normal patterns of emails, conversations, and business practices.

For larger enterprises, Proofpoint Essentials leads the pack with its ability to block twice as many threats as competitors and an impressive 99.99% detection rate .

GlockApps is ideal for high-volume senders. It uses seed list testing to evaluate inbox placement across major ISPs like Gmail, Yahoo, and Outlook. Plans start at $59 per month.

Avanan offers enterprise-level protection, relying on machine learning and natural language processing (NLP) to combat advanced phishing and Business Email Compromise attacks. It processes emails in under 2 seconds with 99% accuracy .

Conclusion

AI-powered spam filtering has dramatically reshaped how we defend against email threats. By moving beyond static blacklists to leveraging behavioral analysis and natural language processing, these advanced tools can now detect and block sophisticated attacks that older systems often overlook. With phishing campaigns incorporating AI in 82.6% of cases and malicious emails being generated 40% faster than before, the need for smarter, adaptive defenses has never been greater.

Choosing the right spam filtering tool depends on your organization's specific requirements. For smaller teams or individual users, affordable and straightforward solutions like Inbox Agents can be a great fit. Mid-sized businesses managing high email volumes might lean toward tools like GlockApps, which offer enterprise-level inbox testing. On the other hand, large enterprises dealing with complex and advanced threats should consider comprehensive solutions like Proofpoint Essentials for more robust protection. This layered approach connects seamlessly with the evaluations shared earlier.

For these tools to perform at their best, it’s essential to ensure your domain has proper SPF, DKIM, and DMARC configurations in place. Additionally, features like Zero-Hour Auto Purge, which can remove threats even after they’ve been delivered, are worth prioritizing.

As directorcia, a Microsoft 365 Expert, explains:

AI models continuously learn and adapt to these new threats in near real-time, significantly reducing the window of vulnerability compared to waiting for manual rule updates.

This ability to adapt in real-time sets modern AI-driven spam filters apart from legacy systems, which still misclassify up to 73.7% of LLM-modified spam as legitimate.

FAQs

How do AI spam filters achieve better accuracy than traditional methods?

AI-powered spam filters have taken email protection to a whole new level by leveraging technologies like machine learning, natural language processing, and behavioral analysis. Unlike old-school rule-based systems, these advanced models can pick up on complex patterns, distinguish between legitimate and harmful emails, and adjust to new threats as they emerge.

One of the standout features of AI filters is their ability to learn continuously from fresh email data. This means they can tackle sophisticated challenges like zero-day attacks or multilingual spam - areas where traditional methods often fall short. With detection accuracy ranging from 95% to 99.9% and false positive rates staying below 1%, these systems deliver a level of reliability that modern inboxes demand.

Inbox Agents takes full advantage of these AI advancements, integrating them seamlessly into its spam filtering system. This ensures businesses get precise, efficient email protection that's tailored to their specific needs.

What should businesses look for in an AI spam filtering tool?

When choosing an AI-powered spam filtering tool, businesses should focus on tools that deliver high accuracy and maintain low false-positive rates. This ensures that important emails don’t end up mistakenly flagged as spam. It's also essential to select a solution with real-time threat detection capabilities, especially for identifying and managing emerging risks like phishing attempts or malware. The best tools use AI models that continuously evolve to stay ahead of new threats.

Additional features to look for include multi-language support, effortless integration with current email systems, and the ability to scale as email traffic grows. Tools that offer compliance support for regulations like GDPR or HIPAA, detailed reporting, and centralized management dashboards can further simplify operations while enhancing security.

Inbox Agents provides a spam filtering solution powered by AI that checks all these boxes. It combines real-time threat detection, adaptability, and a streamlined inbox interface to keep spam out while ensuring smooth communication.

How does Inbox Agents work with popular email platforms to filter spam?

Inbox Agents works effortlessly with popular email services like Gmail and Outlook through secure API connections, including OAuth and IMAP/SMTP protocols. Once you grant access, it processes incoming emails in real time, using advanced AI tools to identify and filter out spam. Any suspicious emails are either sent to the spam folder or kept out of your unified inbox view altogether.

The platform adheres to the security and usage guidelines set by email providers, ensuring a smooth experience for both individual users and large-scale businesses. With handy features like browser extensions and native desktop add-ins, Inbox Agents delivers a consistent, easy-to-use experience across web, desktop, and mobile platforms. Plus, its AI evolves with user feedback, getting better at spotting spam over time.