An email spam filter is a program or tool used to protect our email inboxes from dangers like viruses, and malware and sort out those emails which are unsolicited and junk.
Spam filters look for certain criteria and filter rules set to define an incoming mail as non-spam or spam.
Most business enterprises focus on protecting inbound mail; however, an effective spam filter works on mails coming into an email ID and also on mails going out.
Internet service providers (ISPs), free online email services and businesses use email spam filtering tools to minimize the risk of distributing spam and any unwarranted emails.
Most spam filters identify spam messages by recognizing suspicious word patterns or word frequency, spam URLs and suspicious attachments.
Incorporating an email spam filter not only helps to protect against advanced cyber-attacks but will prevent inboxes from filling up with unproductive junk mail.
Along with this, a user’s inbox preferences based on the emails marked as spam is studied and an algorithm is created for the omission of spam emails.
These spam filters are applied to both inbound and outbound emails with the most commonly used spam filters being for inbound emails.
What Is Inbound Spam Filters?
Mails that are sent to the inbox are known as inbound mails. Inbound spam filtering is the act of filtering email that is sent to your inbox to ensure it is not spam.
When spam is sent to the inbox, email service providers block it with an inbound spam filter.
What Is Outbound Spam Filters?
Mails that leave the system are known as outbound mails and it is highly essential to ensure that spams don’t leave the email system too.
If left unchecked, outbound spam will cause the service provider’s network to be blocked by the rest of the internet — effectively stopping legitimate email traffic for all network customers.
Reputation systems have been established to track the amount of spam coming from each IP address on the internet.
These systems block IP addresses that send too much spam and blacklist them.
What Are the Different Types of Spam Filters?
Blacklist filters block spam emails from senders list added to a list of spammers. These filters are regularly updated with spammers email ids that change relatively quickly.
Content filter verify the contents of each email to determine if an email is a spam or not.
These filters tend to work by checking the spam email content which is often predictable like the deals, or sales content, promoting explicit content or targeting basic human feelings, such as desire and fear.
Header filters analyze email headers to determine if they originated from a legitimate source.
This includes IP addresses recognized as often used by spammers and data indicating that an email was part of multiple emails sent at once to preselected recipients.
Language filters – Spammer send mails in different languages too. Often mails are sent in languages which differ from the recipient’s native language. Language filters help block those messages,
Rule-based filters. Rule-based filters enable users to establish specific rules and apply them to all incoming emails.
Whenever content matches one of the rules, it automatically forwards the email to a spam folder. Filter rules can be specific words or phrases in the message or header.
This type of filter is often popular with users who receive unwanted emails associated with memberships because rule-based filters can also target particular senders.
Why Is Spam Filtering Important?
Spam filters are not a 100% accurate solution. However, an email system without spam filters can be highly vulnerable, if not unusable.
It is essential to minimise spam mails in order to protect your network from many possible risks like viruses, phishing attacks, compromised web links and other malicious content.
Spam filters also prevent the servers from being overloaded with non-essential emails or getting infected with spam software that may turn them into spam servers themselves.
Why Do We Need Spam Filter?
Spam filters are essential to protect email recipients from potential threats. These are mostly in the huge number of unsolicited emails which come in on a daily basis.
They help in blocking viruses, phishing attacks, and segregating safe emails from the potentially dangerous and threating messages.
In an increasingly electronic world, cybercrimes and cyber mischief has caused significant harm to entrepreneurs, businesses and corporations.
Email filtering is a fundamental protection to have in the cyber space.
There’s also a cost implication to not having an effective email spam filtering mechanism. These costs include wasted email capacity, human time spent in dealing with unsolicited mail, server and bandwidth usage etc.
At Exabytes, we looked at some scenarios and came up with a Spam Cost Calculator.
How do Spam Filters Work?
Spam filters helps segregate mails as spam and non-spam emails and identify spam emails.
This identification of spam mails is done with combination of inputs from variety of machines and human-crafted logic to classify messages.
As the name suggests, ‘email filtering’ is at the core of the email security process. The Email spam filtering works on the mail exchange records (MX) of a domain.
It is a gateway solution which works as soon as the MX record of a domain is re-directed to the spam filter.
The analysis is performed on the content (email body), address, header, attachments and language of the mail.
Inbound spam filtering typically identifies the sender by the IP address from which the message originated.
Managing and tracking sender identity in an inbound spam control system is relatively easy, because IP addresses are nearly impossible to falsify (in the context of SMTP email).
Exabytes SpamExperts is a highly effective, accurate and affordable anti-spam solution.
Small, medium and large businesses would find it an easy solution to work with given the increased mail continuity and friendly control panel to work with the tool.
Connect with the Exabytes team to experience an improved and highly efficient email system which is secure. There are some exciting promotions on offer too!
Related article: What Is Phishing Email?