A constantly increasing amount of spam messages in your inbox can be a real problem. Every day that you spend precious time cleaning your inbox manually, takes away time from other activities. And that problem may only get worse in a future, because sending spam is cheap and simple.
With just one click of a button, a spammer can reach hundreds of thousands of addresses quickly. No matter how low of a response rate, there are always people who will respond to an offer. Most spam filters need training by a user, from marking messages manually as spam over a couple of days.
A filter then learns what words and combination of words are regarded as spam, and which ones are not considered spam. Spammers might know this, and are always trying to get around filters. Spam messages many times include genuine text besides a spam message.
This increases a ratio of good text to bad text in a message, which lowers a particular score of a message so that individual spam message is identified as genuine. After marking these messages as spam, a filter is then poisoned with harmless genuine text. This can lead to new legitimate genuine messages being identified as spam, or so called false positives.
False positives can be even more annoying to a user than an actual spam message. When a number of false positives gets too high, a user might regard that filter as useles and even turn it off. If you are tired of using precious time filtering out spam from your inbox, you might want to download Caretaker AntiSpam or similar software.