An unwanted electronic message, most commonly unsolicited bulk email. Typically, spam is sent to multiple recipients who did not ask to receive it. Types include email spam, instant messaging spam, web search-engine spam, spam in blogs, and mobile phone-messaging spam. Spam includes legitimate advertisements, misleading advertisements, and phishing messages designed to trick recipients into giving up personal and financial information. Email messages are not considered spam if a user has signed up to receive them.