Spam Filtering

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Spam Filtering

What is Spam Filtering?

Spam filtering solutions have two main functions:

  • To eliminate and block spam – in the form of unwanted and unsolicited junk emails
  • To protect employees and networks from more sinister email-borne security threats

Did you know that unsolicited emails account for more than half of global email traffic? It is therefore unsurprising that email spam can have a significant impact on performance and productivity levels within an organization, by clogging up users’ mailboxes with reams of unwanted mail, costing thousands of man-hours a year dealing with such messages. Not only that but it also impacts network performance and increases costs by heavily consuming email server bandwidth.

The most serious email-borne threats are found within email content itself however – mainly ‘phishing’ attacks, carried out via infected in-email links or attachments designed to extract sensitive business information or to infect a network with malware. Blocking such emails reaching your end users and employees is of paramount importance in protecting key organization data from being subject to attempted breaches.

The Need for a Spam Filtering Solution

Isn’t there already a spam/junk folder in my email server?

Although basic spam filtering and email content flters do exist on most email platforms, spammers and hackers are extremely sophisticated in their efforts to target end users, and basic spam filters simply do not have the required level of complexity to recognize bogus emails which can be extremely convincing in appearance. As a result a professional spam filtering service is a necessity to fully protect your end users and data. Spam filtering solutions can be hosted on-premise or in the cloud, depending on an organization’s needs.

Spam filters exist for both inbound email and outbound email.

  • Inbound spam filtering scans incoming messages for spam, malware, suspicious links, and attachments, and categorises offending mail depending on their classification.
  • Outbound spam filtering scans outgoing emails, and ensure that employees are adhering to company policy and that no spam, malicious content, or sensitive data ever leaves your organization unauthorised.


How do Email Content Filters work?

Spam filtering solutions identify and catch spam and unsafe emails using multiple security mechanisms, and by incorporating advanced predictive techniques to detect new ransomware and malware variants, phishing and spear phishing attempts, and zero-day attacks. Each incoming message is subjected to a series of checks.

Spam Filtering Techniques

Some of the main spam filtering techniques found in email content filters include:

  • Reputation-Based Email Filters— by filtering out known spammers or approving trusted senders based on reputation databases. Reputation Block Lists (RBLs) are lists of domains, URLs, and IP addresses deemed as possible security threats.
  • Greylisting—Allows an organization to temporarily reject any email from a previously unrecognised sender. If the mail is indeed legitimate, the sending server will be instructed to re-send and the mail will be accepted.
  • Blacklisting/Whitelisting—Provides organizations with the ability to determine which senders – whose mails may have been previously unrecognised or detected as unsolicited - to accept (whitelisting) or block email from (blacklisting) by adding them to a list.
  • Anti-virus technology also inspects incoming emails for malware or URL links to bogus websites that are hidden behind a proxy server. These emails are quarantined, enabling system administrators to determine whether they should be delivered (the sender can also be whitelisted going forward) or deleted.
  • Bayesian Analysis—Organizations can block an email based on its content or attached files, for example messages that contain certain “red flag” phrases. Bayesian analysis learns from each message it scans – the more messages it scans the greater its effectiveness.

Outbound Email Filtering

While the first priority for many organizations is often to evaluate all inbound email, there are numerous reasons to also look at scanning outbound emails for spam and malware.

No matter how trustworthy your in-house personnel are, potentially dangerous emails can be sent inadvertently, but most strikingly there is a very real threat of cybercriminals actually hacking into your business email accounts and using them to send bulk spam emails – perhaps to your clients.

There are numerous educational cyber-security training courses out there that I can mandate my employees to participate in, won’t this suffice?

Increased cyber-security awareness is crucial for any organization, however phishing attacks can be extremely convincing in nature (even in the form of spoof emails apparently addressed from the company CEO) and as per human nature mistakes can and do happen.

A spam filtering service with outbound scanning will identify any attempts to use your business account to send spam email, and block employees sending emails that have may been infected with malware.

If your outgoing business emails end up being caught by other spam filters and are subsequently identified as spam – with your IP address potentially being blacklisted by spam detection agencies – this can result in a substantial loss of business, as well as lost credibility.

Learn more about Email Scanning. 

SpamTitan detects and blocks spam, phishing attacks and prevents email-borne security threats from reaching users' inboxes.

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Why do Spam Filters Exist?

Is it really necessary to invest in an email content filter? My Gmail already stops spam entering my inbox – is this just an added business expense which can be avoided?

Spam is a lucrative business and its volume is growing rapidly. Emails are the most common medium for attacking an organization. While traditional email content filters can stop obvious spam attempts entering your mailbox, hackers are getting more and more sophisticated with phishing attacks.

Eliminate Spam

At best spam is an annoying nuisance that costs thousands of man hours year-round manually dealing with and eliminating unwanted junk mail. Individually, the volume of spam email that evades detection by a default spam email filter may not amount to a lot – maybe four of five per employee per day. However, each spam email takes four or five seconds to identify and delete, and this adds up to hundreds of days of lost productivity each year. Putting this into context, an organization with six hundred employees loses more than 130 days a year if each employee receives five spam emails per day.

Prevent Malware and Phishing Attacks

However on a more sinister note as little as one email can potentially take down a whole organization. All it takes is for one employee to open a phishing email, click on an infected link or attachment which  consists of malware that spreads like a virus in the system. Suddenly the attacker not only has access to the organization’s sensitive data within the hard drive, but they also now have the ability to track every email sent from the organization’s server, giving them potential access to confidential client information, company policies, payroll documents, company accounts information and much more – which can impact the organization’s future as a whole.

"SpamTitan alone has stopped hundreds of thousands of junk and spam emails from eating up employees time trying to sort through them and find actual customer emails. I love this product!" 

M&M Golf Cars LLC

What is the Best Spam Filtering Solution?

When choosing a spam filtering solution it goes without saying, a high spam detection rate needs to be the main priority, however ease of use is also extremely important to ensure you are ultimately using the features correctly and not inadvertently allowing spam to bypass your filter. You also need to carefully consider the features/benefits on offer - do they offer outbound scanning and greylisting for example? Can the claimed levels of spam and virus detection be verified? Is the service scalable and is it compatible with your existing system?

What percentage of emails are blocked by mistake (known as false positives)?

Make sure to check out review sites and testimonials for each vendor. Once your research is completed and your questions have been answered to your satisfaction , only then should you consider the comparative cost of each solution.

SpamTitan Spam Filtering Solution

SpamTitan is a robust and highly effective incoming mail spam filter that uses a range of mechanisms to check each incoming email for a host of spam signatures. SpamTitan email content filters use both Greylisting and Bayesian Analyses to improve detection rates, and can also be set up to scan outbound mails.

SpamTitan blocks 99.97% of spam email, and ensures email continuity in the event of downtime or a server outage.

SpamTitan uses two antivirus engines to check for malware in real-time: Bitdefender and ClamAV. Together, the dual AV engines have a 100% malware detection rate on both incoming and outgoing emails. These figures are verified by VB Bulletin – the leading independent security, testing and certification body.

A spam detection rate this high reduces the average number of spam emails received each day from 14 to 4 – reducing the chances of employees falling for a phishing scam or exposing the network to malware by 72%. Employees would also spend 72% less time identifying and deleting spam emails, enhancing their productivity.

Deployment Options

Our Spam filtering solution is available both as an on-premise solution, ideal for SMBs, and via the cloud, better suited for large organizations and Managed Service Providers (MSPs). Both deployment options are highly scalable with no limits placed on the number of end users or domains. There are no set up costs. SpamTitan is managed via a central administrative portal – rather than as a per-client solution – meaning it has practically no maintenance overheads. Both solutions offer a number of Recipient Verification methods (DRV, LDAP, list-based, regular expression, etc.) and settings that allow businesses to control the login authentication method for each domain.

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"SpamTitan has made a huge difference, allowing me to easily log and track email issues, maintain RFC compliance and provides an easy UI for both myself and my users for their quarantine retrieval needs. The care and attention to detail that went into, and continues to put be into, SpamTitan make it my number 1 recommendation for email security." 

Dowdey, Anderson & Associates

SpamTitan Plus is an advanced phishing protection solution from TitanHQ, it includes A.I driven click time anti-phishing protection. It improves protection against phishing, business email compromise and zero-day attacks by neutralizing malicious links in emails. View SpamTitan Plus product information.


SpamTitan detects and blocks spam, phishing attacks and prevents email-borne security threats from reaching users' inboxes.

Book a Demo

Spam Filtering Frequently Asked Questions (FAQs)

Business anti-spam filters use a variety of methods to prevent spam and malicious emails from entering your employees' inboxes. They offer full integration with Microsoft Exchange, Office 365, Google Apps, and other popular solutions.

Implementing an intelligent, cloud-based spam and phishing filter solution cleans your organization's email and protects against advanced threats. A spam filter service is crucial as the first line of defense against spam.

As the threat landscape continues to rise, deploying an advanced spam filter service within your organization is crucial to leverage advanced email filtering technology to protect your mailbox from the latest threats.

SpamTitan is an award-winning spam filter service built for businesses. Our advanced system filters out more than 99% of unsolicited email from reaching your inbox, keeping your organization's inbox clean and safe.

Spam filtering detects and blocks spam and phishing attacks, preventing email-borne security threats from reaching users' inboxes.

Our simple checklist shows you how to protect your users & organization, detect block spam & phishing attacks & prevent email-borne security threats. Download it for free.


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