E-mail spam is also known as Junk mail or bulk mail. Spam is flooding the Internet with many copies of the same message, in an attempt to force the message on people who would not otherwise choose to receive it. Most spam is commercial advertising, often for dubious products, get-rich-quick schemes, or quasi-legal services. Email spam targets individual users with direct mail messages. Spam has frustrated, confused, and annoyed e-mail users. We can define spam as email that is unsolicited and sent in bulk.
Email spam lists are often created by scanning Usenet postings, stealing Internet mailing lists, or searching the Web for addresses. E-mail addresses are collected from chartrooms, websites, newsgroups, and viruses which harvest users' address books, and are sold to other spammers. One particularly nasty variant of email spam is sending spam to public or private email discussion forums. Because many mailing lists limit activity to their subscribers, spammers will use automated tools to subscribe to as many mailing lists as possible, so that they can grab the lists of addresses, or use the mailing list as a direct target for their attacks. The personal things you can do about spam include never responding to it, filtering it out of your e-mail, and complaining to providers about it.
By filtering the e-mail we can better stop spam. Email filtering is the processing of e-mail to organize it according to specified criteria. Most often this refers to the automatic processing of incoming messages and outgoing emails as well. Email filtering software inputs email. For its output, it might pass the message through unchanged for delivery to the user's mailbox, redirect the message for delivery elsewhere, or even throw the message away. Some mail filters are able to edit messages during processing.