Email filtering and security might seem like something that is just automatically provided by your email provider and is completely out of our hands. Contrary to popular belief, it, like many other general business processes, has ways of being optimised in the interest of security. Email filtering is the process by which a provider monitors your traffic. When considering inbound messages, we normally see this as our emails being moved into Junk before reaching our main inbox. But this also happens when we decide, say, all emails from Dean are sent to a ‘PR’ category, and all emails from Lucy are sent to a ‘high priority’ one. Something else that you might not have realised is that emails that you send are also scanned on the back-end. Outbound emails can also have this functionality, when they’re filtered for being compromised, a scam or anything that is potentially harmful.

Depending on your business operations, there are two main types of email filtering and security. An email filtering appliance may be what your business needs to comply with your industry’s regulations. By using a physical appliance, you’re able to keep all your data on-site, and manage all your ongoing maintenance internally. This will need to be continually updated and upgraded to grow with your business. It is time consuming, and often more expensive than cloud filtering. A cloud email filtering system is much more cost-effective than one which is hardware driven. It allows for seamless migration and expansion within the IT team – as well as the business as a whole. It also means that any security breaches can be dealt from anywhere in the world, 24/7. There is also the option to have a hybrid solution of both cloud and appliance email filtering and security.

How Does it Work?


There are many different ways that emails can be filtered. From simple blocking or email addresses to Bayesian filtering which uses machine learning. The one which is right for your business may not be for another. Making a list of your needs and discussing them with professionals will help ensure you’re meeting your requirements. Here are the most common methods adopted by businesses:

Reputation Based Lists

One way that email filters work to keep you and your files safe is by pooling information from reputation-based lists, or RBLs. If you have a notification asking if this is a trusted sender, or whether something ‘looks like junk’, then the chances are it’s the AI looking to confirm whether or not to trust an email address.

White and Black Lists

Your company may have control over who can send them mail. An  email may only reach you   if it is manually entered in the organisation’s whitelist. On the other side of the coin, there may be blacklisting, which is essentially ‘blocking’, like on social media, but for email. There is also the option for grey-listing, where an email may be held in limbo whilst it is being filtered for malicious content, and then sent along after a period of time has passed.

Content Analysis

One of the most common techniques of email filtering and security. This scans the email for specific trigger words or common phrases in phishing or spam, or denies the email access with attachments. There may be other triggers such as particularly poor grammar, large file sizes, or links to external sites.

Antivirus Scanning

As it says, this technique simply scans the email for known or potential viruses, and malicious code. Emails are the most common way for cyber attacks to occur; hidden code is a common way from cybercriminals to infiltrate even the most savvy of employees.

Why Do I Need it for My Company?


As mentioned above, emails are a highly effective vector for a range of cyber attacks. From phishing for personal information and logins to attachments containing malware, consequences could be dire. Not only can this be leaking of confidential information, it could also affect financials, infrastructure, and the existence of the company as a whole. Not only that, email filtering boosts productivity by streamlining the categorization process and allowing your employees to quickly and easily have access to paper trails and documents.

Best Practices and Suggestions


Double Verification

Emails that have been flagged as spam should still be verified by a human. This makes sure that no potential clients or important updates are missed out upon. Unfortunately AI isn’t always accurate, it doesn’t completely understand the nuances of written communication like a human would!

Update Your Staff

Keep your employees up to date with all the changes that are happening in accordance with your data security and safety protocols.

Perform a Phishing Test

Some companies carry out internal phishing tests in an attempt to educate employees about how easily it can happen. This is not an attempt to name and shame their employees or embarrass anyone. Instead, it’s an educational experience to show how simply people can fall for it.

Contact Us


So, if you’d like to find out more about our email filtering and security services, then get in touch! Contact Nutbourne today on +44 (0) 203 137 7273 or by filling out one of our online enquiry forms on our website. Alternatively, you can talk to one of our agents via ChatBot and we’ll get back to you as quickly as we can.