Before we learn about anti-spam software, we need to first know what is spam. To put it succinctly, spam is unsolicited and unwanted email. Other names for spam are Unsolicited Bulk Mail, Excessive Multi-Posting, and Unsolicited Commercial email, in addition to the more common - spam mail, bulk email or just junk mail. The advent of email brought in an era of instant communication, where information reaches our desktops, at negligible cost, and in no time at all, from across the globe. Along with the benefits, came the negative aspects of email. For the multitudes of marketing hawks out there, this was an opportunity to send unsolicited promotions of their products, instantly, and at a very low cost. Today, spam has reached such monumental proportions that 10 out of every 13 emails (76.9%) we receive are spam, one way or the other. This is why anti-Spam filter has become a must have software for almost all PC users. Stopping Spam Simply put, anti-spam software helps detect spam. It is a software program that detects unsolicited and unwanted e-mail, and prevents them from reaching your inbox. Anti-Spam Filter software is also known by many different names, such as: Spam Filters, Email Spam Filtering, Spam Blocking Software, Anti-Spam Filter, Spam Filtering Software, Spam Blockers, Bayesian Filters, and Anti-Spam, among many others. Anti-spam software is installed in your machine to divert the spam coming in. If installed in the mail server, you will never receive the spam, to begin with. The filtering is configured based on a number of criteria. These could be specific words in the subject line, in the body of the message, and the type of attachments accompanying the mail. You could arrange to filter out even the sender\'s email address. Certain Internet Service Providers (ISPs) maintain a blacklist of habitual spam senders - known as spammers. Anti-spam software detects these blacklisted senders and rejects them per se. Over time, anti-Spam filter has become sophisticated to match with the wiles of the spammers. They use techniques that do not trash genuine emails by effectively analyzing the content of the email. Such software looks for keywords and tries to interpret their meanings in the sentences. Certain spam filters do not accept emails that come to you in the form of \"Undisclosed Recipients.\" They accept emails where your email address is in the \"to\" or \"cc\" fields. Anti-spam software has become an essential part of your computer\'s security, to ensure that you only receive the emails you want, and not others. To help eliminate spam, look for anti-spam software that has the following features, among many others: Blocking emails using both lists and preset filters - blocks specific addresses, watches subject lines, and messages within Updating filters automatically Isolates spam outside of your inbox Puts acceptable emails automatically into your safe list Monitors and filters multiple email accounts Now that you know the basics about the need and importance of anti-Spam filter, select the right one for your computer and get rid of the menace of Spam.