A study by the Radicati Group shows that the average office-based employee is sent 90 emails per day (2016).
It is calculated that, of this total, 14 emails are spam emails that have been delivered undetected by email filters. The research did not indicate how many spam emails were detected and blocked, but at a detection rate of 99.9% (which most advanced spam filter services are capable of) that would suggest an average of 1,400 spam emails are sent to every office-based employee daily.
We have put together a list of features that your anti-spam filter should include.
To allow you best manage threats from phishing, email-borne malware and ransomware, an anti spam filter has multiple mechanisms to calculate the risk level of each inbound email. These mechanisms incorporate acceptable spam thresholds (mentioned earlier), Sender Policy Frameworks, whitelists and blacklists, and recipient verification measures. Each of these mechanisms can be applied by each user, user group or company-wide. (You may, for example, wish to apply more lenient settings for your Sales Department´s emails to stop possible leads being wrongly identified as spam).
Whatever user policies you choose to apply, they should be easy to implement. Setting the acceptable spam thresholds too softly can result in more spam being delivered to employees´ inboxes – setting the thresholds too high can lead to in business-critical emails being quarantined until manually forwarded by an administrator. Luckily, with SpamTitan, you will find our anti spam filter works very well with LDAP and Active Directory to accelerate the simple application of user policies.
Previously, many companies have evaluated their email filtering service based on its inbound email scanning abilities, but there are important reasons why a business should also scan its outbound emails for spam and malware. Hackers are now capable of compromising business email accounts and using them to send large bulk spam emails from a “trusted source”. In these cases, hackers could be using your business email account to share malware with your clients.
An email filtering service with outbound scanning will identify any attempts to use your business account to send spam email, and block employees sending emails that have inadvertently been infected with malware. This step can stop your business email and your business website being incorrectly classified as spam and blacklisted by spam detection agencies. If your emails are blocked, and access to your website is not allowed, it could lead to a substantial loss of business – and credibility.
The “Greylisting” process is one that sparks much debate. It effectively returns every email to its sender – or to be precise, its sender’s mail server – asking for it to be resent. The reason an email filtering service does this is to identify non-genuine email sent from hackers’ IP addresses not yet recorded on Real Time Blacklists and SURBL filtering mechanisms – hackers’ mail servers being too busy to answer the “resend” requests because they are sending out spam emails in bulk.
Greylisting is a brilliant way of catching new sources of spam emails.
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