SpamShield blocks over 99.9% of spam, viruses, malware and other email threats. We provide advanced email security for your business without making it complicated. Unsolicited emails, phishing attempts, spoofing and illicit content are just some of the categories of unwanted email that SpamShield blocks.

Hundreds of advanced tests scan your email separating unwanted email and security threats from the email that you need to run your business. SpamShield keeps learning too, becoming more resilient over time, continuously improving your protection.

Best Spam Filter for Business

The best spam filter for business is not necessarily the highest-rated, the top-seller or the least expensive. There are several different types of spam filter and several different ways in which they can be deployed. Some email filtering solutions are easy to implement and manage, whereas others have high maintenance overheads.

Naturally the best spam filter for business has to have high levels of spam and virus detection, but some email filtering solutions can be over-zealous and block genuine emails. Others can take so long checking for spam and viruses that queues form in the server and potentially important communications are delayed. This article looks at the different types of spam filter and the deployment options available, and considers their pros and cons. It also highlights some of the key features your organization should be looking out for to ensure you select the best spam filter for business for your business´s specific circumstances.

Hardware, Software or Cloud-Based Solution?

Organizations evaluating the best spam filter for business have three choices – hardware appliances, virtual software appliances and cloud based solutions. Due to the developments in technology, it is difficult to make a case for hardware spam filters.

They usually have their own operating systems (requiring individual updates), lack scalability and can be difficult to manage for optimum performance. Virtual software appliances are more versatile and typically operate as a “gateway” between an organization´s firewall and its mail server. Usually compatible with every type of operating system, virtual software appliances have fully automated updating, are scalable, and have simple end user spam management via a web-based interface. Cloud based solutions are the best spam filter for business for SMEs who want to implement their email filtering solution and then forget about it. The implementation of a cloud based email filter simply requires an adjustment to the mail exchanger settings. The service is updated in real time, with the option to schedule reports and adjust the filter´s settings as required.

Key Features of Email Filtering Solutions

Although most “standard” email platforms offer a degree of protection against spam emails and malware, they cannot compete with the increasing sophistication of spammers. 2% – 3% of unwanted or unsafe emails still avoid detection according to Microsoft Outlook´s Benoît Roumagère, and it only takes one click on one malicious URL for an entire organization´s network to be compromised.

Therefore, when evaluating email filtering solutions, the key feature is the percentage of spam emails and unsolicited emails containing malicious URLs the solution blocks. The service provider of the best spam filter for business should demonstrate exceptionally high, verifiable levels of spam and virus detection. Thereafter, organizations should take the following into account: How email identified as spam is treated – quarantined, deleted, or tagged and delivered. The percentage of false positives – i.e. the number of genuine emails that get blocked. The reporting options available to identify false positives and whitelist senders. The front-end tests that are conducted to accelerate the filtering process. The quality of the anti-virus software protecting the organization from malware. Whether a mail continuity service is provided in the event of downtime or server outage. The best spam filter for business should offer organizations the choice of how email is treated and reported. It should provide outbound mail filtering and front-end tests by default – but offer organizations to options to customize these features – and have top-rated anti-virus software for maximum protection. A mail continuity service is essential.

Four Essentials that Every Spam Filter Should Have

Outbound Mail Scanning

Outbound mail scanning checks outbound mail for content that could be mistakenly identified as spam and for malware. As mentioned above, some email filters can be over-zealous and block mail for something as innocent as a misspelled title or the overuse of a spam-related keyword in the email content. Malware could be present in outbound mail if, for example, an employee had prepared a file on their malware-infested home computer and attached it to a company email. If one your organization´s outbound emails is identified as being spam or containing malware, your organization´s IP address could be added to a Realtime Blackhole List. This is a global blacklist of known spammers and their IP addresses against which every spam filter compares every inbound email. To have your emails blocked globally would harm the flow of communication between your organization and your customers and damage your credibility. That is why outbound mail scanning is essential.


Whereas the Realtime Blackhole List contains the IP addresses of known spammers, Greylisting identifies spam from previously unknown sources. Greylisting does this by requesting suspect emails are resent by the originating server. Typically a server sending out spam emails will be too busy to respond, and the request is denied. After a predetermined period of time without receiving a reply, the Greylisting feature classifies the email as spam and it is quarantined, deleted, or tagged on delivery. The reason why Greylisting is an essential feature of the best spam filter for business is that it identifies spam from sources not included on the Realtime Blackhole List and increases the spam detection rate from around 97% to close to 100%. It eliminates the 2% – 3% of unwanted or unsafe emails that avoid detection and keeps your email inboxes virtually free from all types of spam. It is important to note that not all premium spam filtering services include this feature.

Phishing Protection and Malicious URL Blocking

Phishing protection and malicious URL blocking are two elements of antivirus software that prevent the delivery of emails containing links to unsafe websites. These essential features of the best spam filter for business avoid the scenarios in which an employee divulges their login credentials to a cybercriminal or visits a website on which malware exists. Phishing protection and malicious URL blocking also prevents employees from visiting websites hiding their true identity behind a proxy server. Phishing is one of the most serious online security threats in the current environment. A cybercriminal with an employee´s login credentials can use that information to steal or corrupt data. For an organization in a highly-regulated industry, the breach of security could result in large fines and civil action for the failure to implement adequate precautions against data theft or unauthorized exposure. Again, not all premium spam filtering services include this feature.

The Solution : SpamShield

Firefly Cloud´s email filtering solutions are built to be as versatile as your organization needs. We offer a virtual software option – “Firefly
SpamShield Gateway” – and a cloud-hosted option – “Firefly Cloud” – with the complete range of deployment options available.

On their optimum settings, both email filtering solutions block 99.97% of spam, phishing emails and spoofed emails. According to the leading independent testing and certification agency – VB Bulletin – Firefly SpamShield Gateway and Firefly
SpamShield Cloud has a low false positive rating of just 0.03%. Both solutions offer organizations the choice of how they want spam email to be managed, scan outbound mail by default, and run front-end tests such as RBL (Realtime Blackhole Lists), SPF (Sender Policy Framework), Recipient Verification, and SMTP Control Tests on inbound mail in a fraction of a second. Greylisting checks are also run on every suspect email. Double anti-virus protection with phishing protection and malicious URL blocking is provided by two of the leading anti-virus platforms in the industry – Kaspersky Labs and Clam AV – and our easy-to-use service is supported by industry-leading customer and technical assistance. For more than 5,000 customers, Firefly SpamShield has already proven to be the best spam filter for business.