Email Filter for Microsoft Exchange

Implementing the best email filter for Microsoft Exchange is the ideal way to eliminate the unwanted spam that slips through Microsoft´s product, even with “Exchange Online Protection” (EOP). A supplementary email filter can better protect against email-borne threats and ensure email continuity throughout the network during downtime.

The Relationship between Spam and Phishing

Spam and phishing are increasingly interlinked, and AI is also changing the landscape of spam and phishing. In the recent TitanHQ ‘State of email security in 2025’ annual report conducted by Osterman Research, it was found that a priority for security investment is protecting against AI-enhanced attacks. The reason is the recognition of new and emerging threat types with high levels of sophistication and speed.

Phishing and spam lead to a variety of cyberattacks:

Unfortunately, even with additional layers of security on top of Microsoft 365, 79% of companies are still experiencing cyber incidents. These results are consistent even with E3 or E5 and additional layers of security; threats get through. The researchers concluded that email filtering on top of Exchange must be more intelligent.

How the Microsoft Exchange Email Filter Works

Like most other email filters, the Microsoft Exchange email filter uses multi-layered mechanisms to rate each incoming email and assign it a spam confidence level. Incoming emails are compared to a blocklist of known spam sources and analyzed for compliance with sender policy frameworks.

Any incoming email that exceeds a preset spam confidence level is flagged and either quarantined, deleted, or forwarded to its recipient, tagged as spam. The Exchange email filter reports on all quarantined, deleted, or tagged emails so those flagged in error can be reinstated and the email sender included on an allowlist.

Features in a Microsoft Exchange Spam Filter Solution

An email filter for MS Exchange requires enterprise features to support the many facets of a corporate environment. The best-case scenario is a solution that blocks phishing and spam with few false positives and negatives, helping reduce the overhead for administrators. TitanHQ offers several features necessary for superior email protection. Features benefit enterprise administrators, managed service providers, and small-to-midsize businesses that need better security.

TitanHQ Excels in the March Virus Bulletin Test with a 99.99% Phishing Catch Rate, a 100% malware catch rate, & 0.00% False Positive rate.

SpamTitan and PhishTitan, powered by the same cutting-edge filtering engine, showcased their technological superiority in the latest Virus Bulletin assessment. In the Q1 2025 virus bulletin test, the SpamTitan and PhishTitan engines recorded a phishing catch rate of 99.999% and spam catch rate of 99.997%, further solidifying our position as leaders in the industry.

Q1 2025 TitanHQ won a third consecutive VB+ award, achieving another outstanding performance with an overall score of 99.99%.

Spam can be malicious, but it’s also a costly nuisance. Large enterprises might get thousands of spam messages daily, and many spammers target Exchange servers to bypass Microsoft’s integrated security. “Email bombing,” where Exchange servers are overwhelmed by spam, is a Denial of Service (DoS) attack used to turn off a business.

A few general features that can help your business protect digital assets and help administrators deploy better security:

Intelligent Blocking

Research from Osterman strongly recommends that a spam/phishing filter uses innovative technologies like AI:

“This research makes it clear that smaller businesses (with fewer than 1,000 employees) and MSPs need to strengthen their email security protections, as AI-enabled attacks increase and the threat level of a whole set of email threats intensifies. Strengthening email security protections encompasses technical protections that leverage defensive AI capabilities and human risk management investments that create threat-aware, security-competent end users who can identify cyberthreats anywhere, anytime, across any channel.”

Block spam messages from standard risky IP addresses and email servers known to send malicious messages. With continuous updates to risk factor signals, TitanHQ uses various technologies, including AI, to stop incoming threats from reaching recipients. Threat intelligence shared by numerous researchers and security organizations gathers lists of IP addresses from mail servers used for spam, and these IP addresses are factors in blocking spam.

Seamless Integration with Exchange

A mail filter for Exchange must seamlessly integrate with Office 365 and Exchange mail servers. Features should combine an effective spam filter with an API solution, administrator tools, and configuration support with as little overhead as possible. Our seamless M365 integration delivers 360-degree email protection, ensuring proactive defense against phishing, malware, and evolving threats. Safeguarding your inbox against internal and external threats before, during, and after an attack.

Configuration Templates for Fast Setup

Phishing and spam protection with out-of-the-box configurations or your preferences. Setup takes minutes. Deploy SpamTitan and PhishTitan, and your business will be protected immediately. Stay ahead of email threats with two layers of email protection: MX filtering and ICES. This combination provides email perimeter and mailbox protection at the same time. Centralized deployment and management

Centralized deployment control reduces overhead and mistakes if you have multiple administrators. For managed service providers(MSPs), SpamTitan centralizes control of your email security for various clients so that you can more effectively review any issues and secure your customer environments.

Extend and Smart Native MS365 Security

Osterman Research shows that even with an E3 and E5 license, cyberthreats get through:

• 79% of companies suffered cyber incidents even with extra Exchange protection.
• Half of the organizations experienced between 2 and 4 types of incidents.

What this tells us:

1. SMBs are still vulnerable - gaps in M365 security must be filled. We’re seeing that it’s not about more tools, but implementing the right ones, especially those that can close the detection and response gaps that other solutions miss.
2. Layered security is common, but not consistently effective. PhishTitan's current performance has been sensational – for every 80,000 emails received, PhishTitan is catching 20 unique and sophisticated phishing attacks that Microsoft’s elite and expensive E5 premium security is missing.

SpamTitan checks every URL in an email against known blacklists - with 100% active web coverage.

Outbound Spam Email Protection

Spam email isn’t always incoming. Outbound spam email is also an issue, which can result in the corporate Exchange server being put on spam lists. After a business mail server is set on a spam list, any outgoing email will be filtered as spam and won’t reach the intended recipient. Using a spam filter that protects the Exchange server from sending outbound spam messages is essential.

Malware can be built to send outbound spam messages and even phishing attacks using your infrastructure. A good email spam filtering solution protects incoming and outgoing emails. Your Exchange mail filter should stop outgoing spam, malware, phishing, and other nuisance messages. Not every solution supports outgoing email protection, and outbound email is often overlooked in email security.

The danger of ignoring outbound email protection is the risk of your Exchange server being put on a global spam blocklist. Email blocklists are shared among email security vendors, so your email server IP address could be distributed to several blocklists used in filtering solutions. The outcome for your business is that your business email messages are dropped or automatically placed in the recipient’s spam box. The recipient would not receive marketing messages or serious business communications. As you can imagine, this is a serious concern that can interfere with business relationships and revenue.

To make matters worse, manually removing your email server IP address from spam filtering blocklists is time-consuming and requires consistent monitoring to ensure the domain isn’t re-added. While you take steps to remove the email server IP address from blocklists, your marketing emails will likely be sent to spam boxes, negatively impacting your revenue.

Another reason your domain can be blocked is if your outbound messages contain malware. Users with malware on their local machines could unknowingly send malware to recipients; outbound email filters stop malware-infected email messages from leaving your organization and deal with the malware on your behalf.

Malware messages sent to customers can ruin your brand reputation and cause data breaches, violating compliance with standard regulations. Unknowingly sending malware-infected messages to customers can be devastating for any business.

Cutting Edge Consistent Threat Detection

MS Defender can struggle with advanced phishing and sophisticated malware. TitanHQ’s tools have consistently outperformed competitors, with results like a 99.99% phishing catch rate in Virus Bulletin's latest testing. The TitanHQ email security engine showcased its technological excellence in the latest assessment (see section above). In the 2024 Q3, Q4, and Q1 2025 tests, TitanHQ achieved consistent blocking rates and three consecutive VB+ awards, further affirming their leadership in the industry.

1. Email Remediation

The email is automatically removed from the inbox and remediated to the junk folder, streamlining threat management for administrators by eliminating the need for manual intervention and ensuring potential risks are swiftly and efficiently addressed.

2. Warning Banner

A prominent dynamic red banner is automatically added to the email, providing users with a clear and immediate warning about the type of threat. This feature empowers users to recognize and respond to potential risks quickly, enhancing their security awareness and reducing the likelihood of falling victim to threats.

3. Link Protection

All links are dynamically rewritten, ensuring that access to the malicious website is automatically blocked if a user attempts to click on a dangerous link. This safeguard prevents potential harm and provides a critical layer of protection, stopping threats before they can compromise the user or the organization.

4. User-Friendly Admin Interface

With TitanHQ, user interfaces are highly intuitive. Admins report spending significantly less time than they would in other solutions in the portal because it simplifies and accelerates tasks. When admins need to log in, it’s quick and easy to perform necessary actions and move on.

Defender’s admin tasks, such as policy updates and allow/block list management, are reported as being time-consuming. TitanHQ simplifies admin tasks with intuitive interfaces and automation, reducing admin overhead. Admins report faster navigation and less time spent managing alerts.

Within Microsoft Defender, admins must access a specific customer’s tenant, navigate their message trace, and perform tasks like triaging emails or managing allow/block lists on a per-tenant basis. This process is less intuitive and time-consuming, especially when investigating issues or resolving alerts. Reviewing the message trace in Microsoft can be cumbersome and challenging to navigate.

Here are some key features TitanHQ offers that help streamline administrative tasks and reduce costs:

• Auto remediation
• Multi-tenant management
• Cross-tenant remediation
• M365 License Sync with full license utilization, giving visibility into which customers have added licenses.
• Single Pane of TitanHQ Glass
• TitanHQ excels at spoofing, BEC, and social engineering detection, which are the most dangerous and prominent threats.

Time is Money! The time and resources saved using a more streamlined platform like TitanHQ are a clear advantage, particularly for multi-tenant environments.

5. Customization Options

Defenders' preset security policies and fixed detection rules may not offer the flexibility some organizations require. Additionally, Defender does not provide centralized management for multi-tenant environments. MSPs need to access each client’s tenant individually for tasks like message tracing and quarantine management, which can add to the administrative workload.

TitanHQ offers tailored solutions, ensuring MSPs can adapt to client-specific requirements.

Key benefits include:

• Custom detection rules with higher thresholds for indicators
• Centralized multi-tenant management for efficiency

6. Multi-Layered Security

Relying solely on Microsoft 365 creates a single point of failure. TitanHQ’s multi-layered security approach strengthens defenses and mitigates risk. It’s the classic “all your eggs in one basket” scenario—if that single layer is compromised, your entire security framework could be at risk.

Supplementing Microsoft Defender with additional layers of security can address these gaps and provide a more comprehensive protection strategy.

Here are some of the extras you get from TitanHQ:

• Enhanced end-user experience
• No Credit Card Fees
• Dedicated Account Manager & Customer Success Manager
• 24/7 Global Support & Engineering Access
• Sales & Marketing Enablement for MSPs at no cost

The TitanHQ Difference

The TitanHQ platform offers seamless deployment, taking just minutes to onboard. Integrating TitanHQ will simplify workflows, reduce administrative overhead, and deliver improved security and customization tailored to the needs of your client base.

Get in touch to learn more about the TitanHQ Platform or to request a Demo.