What Makes the Best Spam Filtering Service?

Security experts agree the best spam filtering service is compiled of multiple features to protect businesses from excessive levels of spam emails and the threats that accompany them (malware, phishing, ransomware, etc.). What they might not agree on is which features should be given priority when choosing the best spam filtering service for business.

Consequently, we have compiled a list of the top seven features that we believe contribute towards making the best spam filtering service. There is no one-size-fits-all solution, and therefore businesses should decide for themselves which features are most relevant to them in their business environments. The key features of a spam filter service are presented  below in no specific order of priority.


A spam filter service will block the delivery of emails from known sources of spam. Greylisting is used to prevent the delivery of emails from previously unknown sources of spam. This is achieved by returning non-whitelisted emails to their originating servers with a request for the email to be resent. Spammers´ servers often have the mail retry function disabled, and the spam email rarely comes back.

Accelerated Filtering Rates

With fewer spam emails going beyond the Greylisting process, the rate at which remaining emails are filtered is significantly accelerated. This mitigates any delays attributable to the Greylisting process and reduces the administrative burden of whitelisting multiple “trusted” senders in order to avoid delays in the delivery of their emails.

Outbound Email Scanning

Outbound email scanning is a valuable security tool for identifying business email accounts that may have been compromised and are being used as “trusted” senders to distribute spam or malware. Not only might this save a business from an internal threat, but also protect their reputation with business partners and other important entities.

Advanced Anti-Virus Software

Most anti-virus software works by scanning devices and networks for the presence of malware after it has been deployed. The best spam filtering service will scan inbound and outbound emails and their attachments for malware as they flow through the mail server in order to identify threats before they have the opportunity to be deployed.

Phishing Protection/Malicious URL Blocking

This feature compares links in the body of emails against a database of malicious URLs known to have been included in previous phishing emails. Malicious URL blocking can prevent the most carefully-crafted spear phishing attack from reaching its destination, and adds the sender´s IP address to the database in order to block future attempts using a different URL.

Data Leak Protection

Data leak protection is a relatively new development in email filtering. It allows the tagging of user-defined keywords so that if an outbound email containing a tagged keyword passes through the filtering service, the email is flagged or blocked. This feature is designed to stop the leak of confidential data, either to a malicious actor or from a malicious insider.

Ease of Operation

The best email filtering service in the world may not be of value to businesses if it is too complicated to configure. Therefore, whatever solution is chosen to protect businesses from excessive levels of spam emails and the threats that accompany them must be user-friendly for customizing the service to the business´s specific security requirements.

Adding an Email Filtering Service to Office 365

Microsoft Office 365 includes some email security features as standard in its Exchange Online Protection (EOP) feature; however, many businesses find the basic level of protection provided by Microsoft’s email filtering service falls short of requirements. The email filter in Office 365 does a reasonable job of blocking spam from know malicious sources, but it is not so effective at blocking phishing emails and zero-day malware threats, which often sneak past EOP.

To improve protection you need to use a third-party email filtering service to add another layer of security to Office 365. In contrast to Office 365’s standard email filtering service, SpamTitan uses machine learning techniques to identify new phishing threats that have not been seen before. Greylisting is used to identify new sources of spam and phishing emails, and sandboxing is used to isolate zero-day malware threats in safe environments. These features are not provided in Microsoft’s EOP email filtering service.

Is SpamTitan Email Filtering the Best Spam Filtering Service for Business?

If your current filtering service does not support all these features, you could be experiencing a higher level of spam and email-borne threats than necessary. The SpamTitan spam filtering service offers all these features – and more – to achieve spam detection rates of 99.97%. If you would like to know more about SpamTitan – and whether it could be the best spam filtering service for your business – do not hesitate to get in touch.

Our team of Sales Technicians will talk you through the deployment options, the email continuity service, and much more before inviting you to see SpamTitan in action in a free demo. This offer gives you the opportunity to experience our feature-rich spam filter service, discover how easy it is to use, and evaluate which deployment option is the best for your business.


Will a spam filtering service block email impersonation attacks?

To block email impersonation attacks, a spam filtering service will need to incorporate email authentication protocols such as Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication Reporting and Conformance (DMARC). These protocols are used to authenticate emails to prevent the impersonation of known or trusted individuals.

How can a spam filtering service block ransomware attacks?

Cyber threat actors use a variety of methods for gaining access to networks to deploy ransomware, such as using stolen credentials, brute-forcing weak passwords, or exploiting unpatched vulnerabilities. However, the main method of getting a foothold in networks is through phishing emails. A spam filtering service will block virtually all of these malicious messages.

Why is sandboxing important in a spam filtering service?

A spam filtering service will include a signature-based antivirus engine. When a new malware variant is identified, the signature will be added to the virus definition list which will allow the malware to be identified and blocked. Signature-based antivirus engines will not detect brand new malware variants. Sandboxing addresses this gap by analyzing the behavior of email attachments to identify malicious actions.

What is SpamTitan Plus?

SpamTitan Plus is a new AI-based spam filtering service from TitanHQ that provides unrivaled protection against zero-day phishing threats and malicious URLs in spam and phishing emails. The solution includes coverage of 100% of existing phishing feeds, detects 10 million new phishing URLs daily, and has 1.5x more unique detections and 1.6x faster detections than the current market-leading phishing solutions.

What Features are Enhanced in SpamTitan Plus?

SpamTitan Plus performs URL rewriting to check whether the URL provided in the message body is safe. With many spam filters, the URL is checked and emails are delivered to inboxes if the embedded URL is determined to be safe; however, if the linked web page is changed to host malicious content after the email is delivered, the threat will not be blocked. That is why SpamTitan’s time-of-click protection is important. The solution is also updated from massive clickstream traffic of 600+ million users and endpoints ensuring unrivalled detection of malicious URLs in emails.