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How does spam filtering work

How Does Spam Filtering Work?

It’s hard to imagine modern life without spam filtering. Billions of junk emails never hit our inboxes because of this valuable innovation. Spam filters are unsung heroes of cybersecurity, saving internet users countless hours and headaches every single day. They diligently run in the background and protect us from malware, malicious links, and phishing attempts. While no spam filter is perfect, it’s almost always a good idea to use one.

What Is a Spam Filter? 

Spam filters function to keep unwelcome emails out of users’ inboxes. Though not all spam is harmful, it quickly takes up valuable storage space and makes finding legitimate messages more difficult. Users may change their spam settings at will, but they generally don’t have to, and most major email providers enable spam filters by default. 

Spam filters greatly reduce the amount of human error involved in email communication. Because employees are often the first line of defense against cybercriminals, it’s only a matter of time before someone makes a mistake. A single click or harmful download can compromise an entire company network, and spam filters work to counteract this.

Spam filters can usually tell the difference between malicious and harmless emails. They help ensure that email platforms are functional and user-friendly for everyone. Filters also create an added layer of security given that email is one of the most common attack vectors facing companies today. They also protect networks and workstations from data breaches, reducing the amount of downtime needed for incident response. 

How Spam Filtering Works 

There are various kinds of spam filters available today. The best ones run without much input from the user, regardless of their exact process. Traditional filters relied on users to flag malicious emails themselves, but innovations in AI and machine learning now play a greater role. 

Content filters automatically sift through the text of emails before they arrive. This process is straightforward because most spam emails include predictable language and content. Spam often promotes so-called deals, explicit material, and emotional reactions from recipients. Content filters search for repeated keywords like “offer,” “discount, “urgent,” and “limited time.” 

Blacklist filters also block emails from malicious senders. These useful tools create a record of domains and IP addresses flagged by other spam filters. ISPs then cross-reference inbound emails with this record and prevent matches from ever reaching the user’s inbox. Companies can also update their own list of spam addresses to a personal blacklist. This allows them to filter out emails from headhunters, sales departments, or marketing firms that would distract their employees.

Another form of filter examines the headers of emails. These header filters watch for IP addresses commonly used by scammers and screen their contents from inboxes. They may also assess whether an email copy was sent to multiple addresses at the same time. Attackers often employ this tactic after stealing a list of contacts from companies.

Bayesian filters set up rules as they learn your preferences. Over time, they recognize patterns in your email behavior. If you always flag promotional emails or those from a certain sender, a Bayesian filter will quickly catch on and act accordingly. Your preferences will apply to future emails automatically, saving you time while protecting your inbox from attackers. 

Spam Filters Help Businesses Succeed 

Though the number of spam emails is decreasing, they aren’t going away anytime soon. They pose a constant threat to companies and individuals alike, and it’s always best to take them seriously. Spam filtering is necessary to safeguard any business’s data, clients, and employees from malicious actors. If your company doesn’t use a spam filter, contact us today to see how we can help. Our team is eager to support your unique IT needs throughout the digital age. 

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