Spam filtering, otherwise known as email filtering, is a process wherein a special software or hardware filter organizes the incoming messages of your inbox according to the specified criteria that you, the user, have specified. More often than not, the procedure refers to automatic email processing via software or hardware filters, but it eventually became applicable to sent emails as well as incoming ones and human intelligence intervention that had been integrated with standard anti-spamming techniques.
Typical spam filter features include removal of unsolicited mail (hence its name) and computer viruses or other malicious code that's attached to a message. These programs are infrequently employed to analyze outgoing emails as well by some corporations in order to guarantee that staff and workers aren't doing anything illegal with company resources. Then there are users who utilize these filters to prioritize important messages from unimportant ones or to better manage their email by sorting them into folders based on subject matter or other stipulations. For a supposedly one-trick-pony application, the spam filter is a lot more versatile than it initially seems.
Spam filters usually input email, while the passage of an unaltered message for delivery to the user's mailbox serves as its output function. These security tools can also throw the outgoing message away or redirect it for delivery elsewhere depending on their settings. Then again, there are email filters capable of modifying or editing messages during the processing stage of its operation. Spam filters are available as part of an email client (i.e., an extra service of sorts) or as a standalone, external software.
Nowadays, a lot of email clients already sport filters as a basic feature. These programs allow users to create customized, manual filters that automatically block unwanted or unsolicited email according to their custom preferences. Moreover, most email applications have an automatic spam filtering procedure too; in fact, you'd be more hard-pressed to find a client that doesn't have this widespread service. ISPs (Internet service providers) can also install these filters in their email transferring agents at the behest of their customers. Major corporations also use filters as a security measure that protects their interests, assets, data, and employees from common spam-related threats.