With the advancement in science and technology, emails have been a wonderful source of connecting people from all over the world. Emails are used to flow your ideas, messages, thoughts, and much more with just a single click. But with the overwhelming use of emails, there is something that acts as a villain in our inboxes. These are spam emails. No matter if you have subscribed to a certain website, page, or blog you are still going to find them waiting in your inbox ready to annoy you and waste your precious time.

Email spam filters are the heroes created to protect you from this trouble. They help you from getting those spam messages. But are you wondering if these email spam filters really work? Let’s dive into this article to explore how these guardian angels protect your inbox from spam, if their cutting-edge technology really works, and if yes then how?

What is Spam?

Span is an unwanted and unsolicited digital message usually sent out in bulk. Spam can be sent through emails, text messages, or even calls. Email spam is also referred to as junk email, spam mail, or simply spam. This unique name comes from a Monty Python sketch. In this sketch, the name of a canned pork product is spam which is repetitive and unavoidable just like spam mail.

Types of Spam

There are different kinds of spam found on the internet. The most popular are mentioned here in detail.

Marketing and Advertisements

This is one of the best marketing strategies and the most common type of spam on the internet. The aim of this is to convince you to buy something. It could be anything clothes, shoes, food products, or even furniture. There is a possibility that it might be a scam or it could be authentic.


Phishing is considered to be a dangerous type of spam. In this type, the attacker pretends to be someone else, someone with some sort of authority. He or she can convince you or force you to take some sort of action for them like buying something.

Money Scams

These are the type of scams to get your banking information in some way. Later on, they use your banking information to wire up some money from you. Spammers can send you some false lottery-winning emails and can trick you into giving your bank information.

Malware Warnings

These are the emails sent by the spammers to warn you that your computer has been infected with some sort of virus or malware. To resolve this issue, you need to install software or click on an ad, etc. This malicious email can lead you to give the information the attacker needed. These are the simple tricks to lure people into downloading their virus and getting what they want.

What is a Spam Filter?

These are the algorithms used to detect undesired, unsolicited, and infected emails. A spam filter prevents such emails from reaching your inbox. There are many different types of spam filters with different types of capabilities. We will discuss these filters in the next headings. Their main goal is to block all unwanted emails which may cause you any sort of disturbance.

How Do Spam Filters Work?

Spam filters work by following some basic detection methods. Earlier, these filters detected certain keywords being used in the spam mail and they filtered out such mails containing those words. With the advancement of spam filters, the spammers also advanced. Instead of using the well-known keyword in their emails, they have changed their design of constructing spam mail. Mainly spam filters work by detecting the following aspects:

  • Content of the mail
  • Authority of the sender
  • Engagement between the email and the sender

Types of Spam Filters

As already mentioned, the main aim of this filter is to keep unwanted mail out of your inbox, and for that, there are different filters. These spam filters work through different techniques. Let’s look into a list of them and their filtering methods.

Content Filters

Content filters work by analyzing the content of the email. After analyzing it decides whether to send that email to spam or not. The content of a spam email is easily detectable most of the time. They have some sort of deals or promotions offered in them. Use of words such as ”limited time offer,” ”discount” etc. are common in such emails. Any inappropriate language indicating explicit content is also detected by the content filters.

Blacklist Filters

Senders that have already been on the spammer’s list are detected by the blacklist filters. These filters block the emails received from such senders. As spammers change their email ids frequently, blacklist filters are updated regularly. Once a spammer changes his email id, his spam mail might be sent but once again he will be detected by the blacklist filters.

Header Filters

As the name suggests, header filters detect spam mail from the header of the email. It checks the header to see whether the email received from the sender is from an illegitimate source or not. These filters can detect the IP address of the spammer. They are also able to detect if the email was a copy of many emails sent at one time.

Language Filters

Language filters detect the language of the email being received by the receiver. If this language is different from the recipient’s language, then it is most likely that the email will be sent to spam. This happens when spammers try to target people from different countries. It should be noted that a legitimate email from a business connection from another country might be detected by the language filters and then sent to the spam folder. So, in such cases, the person is advised to check their spam folder as well so they do not miss an important email.

Rule-Based Filters

In this type of filter, you have the advantage of setting up your own rules for detecting an email as spam. You can choose certain phrases or words to be detected in the email body. If any of those words or phrases are found in the email then that specific email will be sent straight to the spam folder.

Bayesian Filter

Bayesian filters can observe and learn your preferences. This filter notes the emails which you mark as spam, remembers them, and set their rules according to your preference. In this way, you will not get new emails with the same content which you marked as spam before in your inbox. This filter even detects the sender whose emails you mark as spam and any emails from that sender will be sent automatically to the spam folder in the future.

Does an Email Spam Filter Really Work?

Although spam filters are highly efficient, they are not considered 100% accurate. There are chances that some emails might go undetected by the spam filters. However, Gmail is a renowned mailing platform with over 1.5 million users claims to have 99.9% accuracy in filtering the spam emails received on their network. As the technology is evolving there are chances of more innovations in spam filtering features.

Why Spam Filters Exist?

Spam filters exist to make the user experience free of any disturbance. Spam emails can fill up your inbox and cause some serious storage issues for you. To avoid this issue, spam filters exist so that you don’t need to upgrade to larger storage. Spam can also contain malware or virus which can harm your device. If the email provider or that company is unable to stop such emails from getting to you then it gains a bad reputation. Spam filters exist to enhance the user experience and protect the service provider’s reputation.

What are the Different Ways to Reduce Spam?

stop email spam

If you are receiving plenty of spam and are tired of it then no need to worry. Dealing with email spam is child’s play by applying the guide below. These are some great ways for you to reduce your spam.

  • If you receive a malicious email, it is advised not to interact with it in any way. If you unsubscribe it, you send the signal to the spammer that your account is active. In such cases, they may send you more spam emails. So, it’s better not to unsubscribe.
  • For the Bayesian filter to work it is important to mark spam emails as spam. Only then the filter will be able to prevent you from similar emails in the future.
  • Many email providers are offering very strong rule-based filters. However, they will not be active until you customize them by adding phrases to them. it is advised to set up the rule-based filters as soon as possible to avoid spam.
  • If you are not satisfied with the spam filters already provided to you by the spam filters then you can get spam filters externally. There is a wide variety of spam filters available on the internet which are either free or paid. You can install them and can get customized spam filters.
  • It is important to avoid giving out your email address very often. When your email is shared, the recipient has the opportunity to send you spam mail. So, try to keep your email address as private as you can.

The Bottom Line

Spam emails are unwanted and unsolicited emails received in your inbox. Spam exists in the form of advertisements, phishing, money scams, and malware warnings. Technology introduced great spam filters to prevent these emails from getting into your inbox. Different spam filters use different filtering techniques but all of them have the same goal to block unwanted emails. Some common filters are content, blacklist, header, language, rule-based, and Bayesian. However, these do not provide 100% accuracy despite being very efficient.


What is the best spam filter?

Which spam filter suits you depends on the challenges of your business. But for most people, Bayesian filter is considered the best option as it automatically learns which emails are spam according to you.

Do spam emails eventually stop?

It is impossible to stop all the spam emails as there are so many scammers who never stop sending these emails. However, by adopting certain precautions you can avoid plenty of spam emails.

Can a custom email address be saved by email spam?

It is recommended to use secured servers or VPS by a reliable hosting company if you want to use the custom email that ends at your company website name like @hostosite.com.

What are the disadvantages of spam filtering?

The disadvantage of spam filtering is the chance of false positives. Before a spammer’s email ID or domain is detected or blocked, thousands of spam emails are sent already. In cases where large portions of legitimate text are used, Bayesian filters can easily get fooled.

Why do most emails go to spam?

Most email providers judge your activity by how many emails you open and read and how many stay unopened. They observe this to make decisions for spam filtering. For this reason, low-opened and read emails will be sent to the spam folder. It is advised to maintain engagement.

How do I use a spam filter?

To use a spam filter, first scroll to the ‘’SPAM’’ option and then click on ‘’configure’’ or ‘’ADD another rule.’’ Enter a name for the setting in the ‘’add setting box.’’ Then turn on the more aggressive spam filtering.

Can spam filters remove viruses?

Spam filters can detect viruses in the spam emails. They send such virus-containing emails straight to the spam folder preventing you from installing any malware or virus in your computer.