Spam has evolved from a nuisance into a significant cyber threat for businesses. A gateway spam filter is an on-premises software solution designed to filter email and mitigate this risk. Typically installed as a virtual appliance behind the network firewall, it blocks most spam emails, ensuring only legitimate and safe emails reach their destination. Alternatively, cloud-based spam filters are also available. The two choices depend on your business’s specific needs and criteria.
Anti-spam gateway solutions, both on-premises and cloud-based, can positively impact network security. Tests have shown that anti-spam gateway solutions can detect 99.9% of spam and reduce a network´s exposure to email-borne threats such as phishing, malware, and ransomware. Here, we look at what a spam filter gateway is and which one may be the best fit for your business.
On-premises or a cloud-based spam gateway?
The best spam filter for your business will depend on the specific needs of your business and the level of protection required. Despite the trend towards cloud deployment, and software-as-a-service (SaaS), some companies may prefer on-premises spam filter gateways that are within the bounds of their corporate network. For example, a business may be subject to stringent federal or state regulations regarding the security, visibility, and accessibility of data. They may also have concerns about connectivity and latency because of their location. On-premises solutions can also be more customizable than cloud-based solutions.
Cloud-based spam gateways may seem like a good choice, but traditional on-premises mail servers with spam filters can offer some benefits, including the following:
- Control: On-premises spam gateways may provide more fine-grained control and accessibility over the flow of emails.
- Maintaining confidentiality: An on-premises spam filter is maintained within the organization’s network.
- Easier troubleshooting: On-premises access to a spam filter may provide easier troubleshooting of mail issues.
- Business Continuity: An enterprise could be out of business if a cloud service goes down. Business disaster and continuity must be handled in an SLA using a Cloud-based email filter gateway.
In terms of spam filter gateway effectiveness, there is little difference between a gateway spam filter and a cloud-based spam filter. Both solutions are equally good at detecting spam (assuming they offer the same features and settings) and require little maintenance. Updates are performed by the service provider, who also provides technical support to guide businesses through any issues.
Why do I need a spam filter gateway?
The amount of spam generated daily is phenomenal. Recent estimates are that almost 46% of the 347 billion emails sent and received daily are spam. Individual businesses may deal with thousands of spam emails every month. This volume of spam causes employees’ inboxes to fill up, causing them to miss legitimate emails. Time is lost while employees wade through emails and delete spam. However, what is more concerning is that spam may contain malicious content or could be part of a broader social engineering scam.
In 2023, 40% of attackers used email to initiate harmful attacks on organizations. Email continues to be the main way to enter a corporation’s network; spam and phishing are used to manipulate staff into handing over login credentials or navigating to spoof websites. Ransomware is a case in point. Spam emails may seem innocuous, but an MSP survey from Statistica found that 54% of attacks originated from phishing or spam emails.
A spam filter gateway, which is either a virtual appliance or a cloud-based spam filter gateway, will stop almost all spam before it enters corporate inboxes.
Critical features of anti-spam gateway solutions
If your business is considering implementing a spam filter gateway, it is essential to note that not all anti-spam filter solutions are the same. Understanding the differences is critical to making the right decisions about which gateway is best for your company.
All anti-spam gateway solutions use real-time blocklists to stop malicious emails sent from known spam sources. However, more than this technique will be needed to stop persistent, emerging, zero-day, or multi-part spam. Essential features to look for in on-premises spam filter gateways include:
Greylisting
Greylisting is an effective process that prevents emails from previously unknown sources from entering the network. This technique is used in more advanced spam filter gateways. Greylisting compares the “SMTP triplet,” i.e., the sender's email, recipient email, and incoming mail server IP address, against a known senders database. An unrecognized triplet temporarily rejects the email and returns it to the sender's server. If the sender is legitimate the mail server will attempt to resend the email. However, because of the way spam servers work, sending out millions of emails automatically, the likelihood of spam emails being resent is minimal.
Malicious URL interception
Similarly, most anti-spam gateway solutions have Recipient Verification and Sender Policy Framework tools to enhance email security. Few have SUBRL filtering to detect malicious URLs. This feature can help reduce the network exposure to phishing attempts. With fewer phishing emails delivered, there is less likelihood of a user revealing login credentials or other sensitive information.
Sandboxing
Sandboxing is a valuable fallback feature that adds control to the spam identification process. Sandboxing allows for detecting and isolating files suspected of containing malware so they can be further analyzed. Suspicious emails are sent to a sandbox for check by a human being. The sandbox is a safe environment allowing an administrator to open emails, check malicious links, and use anti-malware tools to test malware. The email can be forwarded to the original recipient if it is safe. The sandbox also keeps track of malicious signals, adding them to known attack types so that any repeat attacks will be automatically stopped.
A layered approach to spam
Cybercriminals are adept at creating spam and malware-laden spam designed to evade detection. Keeping up with the never-ending array of evasive tactics means that a spam filter appliance and gateway must use intelligent measures to adapt and predict these market forces. Advanced spam gateways must use intelligent measures to handle evasive and emerging threats. Some of the techniques used by a spam gateway, like SpamTitan Gateway, include antivirus software, Bayesian analysis, real-time blocklists (RBLs), lists of websites that were detected in unsolicited emails (SURBLs), and sender policy frameworks. These layers add increasingly adaptive techniques to capture almost 100% of spam emails.
The benefits of an outbound secure email gateway
Spam is a two-way problem. Outbound emails can potentially be identified as spam, causing problems for a company’s brand and resulting in a blocklisted IP address. A spam filter gateway or filter appliance can be used to identify outbound and inbound spam. An outbound secure email gateway allocates a Spam Confidence Score to each outbound email and inspects it for malware. If the Spam Confidence Score is too high or contains malware, the email is quarantined, and a report is sent to the network administrator.
This process prevents a business´s IP address from being blocked by global block list agencies for high levels of spam – a scenario that could occur inadvertently or if a cybercriminal has compromised a corporate email account and is being used to send spam from a “trusted source”. The process also flags malware on the network that has not yet been identified by antivirus software.
Try SpamTitan Gateway spam filter for free.
TitanHQ has been developing online security solutions since 1999. We work closely with clients, MSPs, and other industry vendors to deliver exemplary email security. However, we understand that for any online security solution to be effective, it must be straightforward and configurable for various business scenarios. Therefore, we have designed our gateway spam filter to have the lowest maintenance overheads and the maximum user-friendliness.
Our gateway spam filter is simple to install, configure, and manage. User policies can be imported via directory synchronization or applied via a web-based administration portal. Spam Confidence Levels can be used universally or by individual user/user groups as required, and from the portal, network administrators can drill down into historical data to conduct risk assessments and identify sources of email-borne threats.
SpamTitan´s gateway spam filter includes all the core features an effective spam filter gateway requires. An external test organization validates this effectiveness, Virus Bulletin:
Catch rate 99.98%
False positives 0.00%
Malware catch rate 100%
The success of SpamTitan Gateway is down to the use of multiple layers to catch even emerging spam and malware. Using dual antivirus software gives SpamTitan a 100% record of capturing inbound and outbound viruses.
SpamTitan comes with advanced features for IP protection control to ensure that outbound emails do not damage your brand.
Furthermore, SpamTitan is infinitely scalable, as it can protect any number of users or domains.
SpamTitan is universally compatible with every type of operating system.
- SpamTitan´s gateway spam filter is ideal for businesses wishing to keep their email security “in-house.”
- Features include greylisting to identify spam from previously unknown sources and SUBRL filtering to detect malicious URLs.
- Outbound scanning helps identify compromised email accounts and account abuses to protect the business´s IP reputation.
- Our gateway spam filter takes just minutes to install and is easily managed via a centralized administration portal.
To learn more about the features of SpamTitan´s gateway spam filter, and to request a free trial to evaluate SpamTitan in your environment.
Our Sales Technicians will happily answer your questions about our anti-spam gateway solution and explain more about how the secure email gateway will work in your circumstances. There is never a wrong time to reduce spam and your exposure to email-borne threats, so contact us today.
FAQs
Why should a gateway spam filter include Greylisting?
A gateway spam filter should include Greylisting to reduce the number of spam emails evading front-end tests. The Greylisting process is a simple but effective way to identify and mitigate spam. The method returns all non-allow-listed emails to the sender’s server with a request to resubmit them. Because of the number of emails returned to spammers’ servers, the resubmit function is usually disabled, and the spam email is never returned – reducing the demand on the mail filter and ensuring genuine emails are processed promptly.
What is a Spam Confidence Score?
A Spam Confidence Score is a value assigned to an email by a spam filter. Rules are used to designate the Spam Confidence Score. The score triggers a rule for quarantine, deletion, or safe to send. Email evaluation for scoring is based on multiple layers of analysis, including Bayesian analysis, which looks at how words are composed to identify idiosyncrasies. Spam Confidence Scores can be adjusted to fine-tune a company's approach to checking for spam.
Is a spam filter gateway all I need to block phishing attacks?
A spam filter gateway is one measure of a consolidated approach to block phishing attacks. The continuing attempts by cybercriminals to evade detection by antispam and anti-phishing technologies means that one method of control will provide only a portion of the protection. Multi-layered defenses are recommended to provide the best possible protection. An anti-spam gateway can be combined with additional measures, including a web filter to block the web-based component of phishing attacks and security awareness training to empower employees to spot social engineering and phishing.
Is security awareness training for the workforce necessary if I have a mail gateway spam filter?
Security awareness training for the workforce is a best practice for every business, even if a mail gateway spam filter is deployed. Because of the evolutionary nature of email-borne cyberattacks, an email gateway spam filter will not block every malicious message. It may only take a single interaction with a phishing email to result in a cyber-attack. As such, regular security awareness training should be a consideration when building a robust security posture. Security awareness training is provided to the workforce to teach employees how to identify phishing emails and follow cybersecurity best practices. Security awareness training typically involves phishing simulation exercises to help understand phishing tactics.
How much does an anti-spam email gateway cost?
The cost of an anti-spam email gateway can vary considerably depending on the solution's features. However, cost-effective solutions are available. TitanHQ designed our advanced anti-spam email gateway, SpamTitan, to be affordable for even small companies. SpamTitan will protect you from all email threats for as little as $12 per user per year.
Does SpamTitan include a sandbox?
SpamTitan includes a sandbox powered by Bitdefender. The sandbox uses dual antivirus engines to protect users from malware and ransomware threats better. Unknown files and suspicious attachments flagged by AV checks are sent to the sandbox for in-depth analysis. This allows SpamTitan to block new malware variants that have not yet had their signatures incorporated into the virus definition lists of the AV engines.
Who decides whether an email is tagged as spam, quarantined, or deleted?
Who decides whether an email is tagged as spam, quarantined, or deleted is usually the organization’s system administrator (usually someone in the IT department) or a Managed Service Provider if a small business subscribes to a gateway spam filter via a service reseller. The Spam Confidence Score rules can be flexible to allow some spam emails to be tagged as spam and forwarded to a user’s inbox with a warning. However, it may make more sense to quarantine suspicious attachments or delete suspicious emails sent to users with a known susceptibility to phishing.
How might a cybercriminal compromise a corporate email account?
The most common way a cybercriminal can compromise a corporate email account is to trick a member of the workforce into revealing their login credentials via a phishing email. After that, the cybercriminal may use the compromised account to spam or exploit the trusted source to send further phishing or BEC emails.
How can an anti-spam gateway solution help reduce the network exposure to phishing attempts?
An anti-spam gateway solution can help reduce network exposure to phishing attempts via “point-of-click” SUBRL checks. These checks run embedded URLs through a further check when the link is clicked to ensure a link that passed the filtering controls when it was delivered to the user has not since been weaponized or used to trick users into revealing account credentials.