E-mail is an indispensable communication tool, as it provides a reliable, fast, and free way to communicate with others. Unfortunately, it too has its downsides when you receive mail that is inappropriate, unsolicited, unwanted, or irrelevant. Spammers often flood your inbox with promises of free vacations, free credit repair, dramatic weight loss, advance loans, free adult entertainment, and much more. Some spam has become even more potentially damaging. "Phishing" is a form of spam that fraudulently misrepresents the sender as a trusted authority, e.g., your bank, a social networking service, even the University. The phisher's intent is to acquire sensitive personal information about you, such as your Social Security number, your birth date, or credit card and banking information. Spam and phishing are multi-billion dollar industries aimed at exploiting and defrauding you. You should use the tips and tools described in this section as well as your common sense to keep yourself safe while using e-mail.